WO2018120518A1

WO2018120518A1 - Nanocrystal, manufacturing method, and semiconductor device

Info

Publication number: WO2018120518A1
Application number: PCT/CN2017/080623
Authority: WO
Inventors: 刘政; 杨一行; 钱磊
Original assignee: Tcl集团股份有限公司
Priority date: 2016-12-30
Filing date: 2017-04-14
Publication date: 2018-07-05
Also published as: CN108269893A; CN108269893B

Abstract

A nanocrystal, manufacturing method, and semiconductor device. The nanocrystal comprises S central structure units located at a center portion, and N surrounding structure units located outside of the center portion. The central structure units and surrounding structure units are quantum-dot structure units. The central structure units are a graded-composition alloy structure having an increasing energy level width from an inner side to an outer side in a radial direction. The N surrounding structure units consists of M first surrounding structure units and (N-M) second surrounding structure units, the M first surrounding structure units are a uniform composition structure having a consistent energy level width in the radial direction, and the second surrounding structure units are a graded-composition alloy structure having an increasing energy level width from the inner side to the outer side in the radial direction. At least one of the first surrounding structure units is located between the second surrounding structure units and the central structure units, the energy levels of adjacent central structure units are continuous, and the energy levels of adjacent second surrounding structure units are also continuous.

Description

一种纳米晶体、制备方法及半导体器件Nano crystal, preparation method and semiconductor device

技术领域Technical field

本发明涉及纳米晶体领域，尤其涉及一种纳米晶体、制备方法及半导体器件。The invention relates to the field of nanocrystals, in particular to a nanocrystal, a preparation method and a semiconductor device.

背景技术Background technique

量子点是一种在三个维度尺寸上均被限制在纳米数量级的特殊材料，这种显著的量子限域效应使得量子点具有了诸多独特的纳米性质：发射波长连续可调、发光波长窄、吸收光谱宽、发光强度高、荧光寿命长以及生物相容性好等。这些特点使得量子点在平板显示、固态照明、光伏太阳能、生物标记等领域均具有广泛的应用前景。尤其是在平板显示应用方面，基于量子点材料的量子点电致发光二极管器件(Quantum dot light‐emitting diodes，QLED)借助于量子点纳米材料的特性和优化，已经在显示画质、器件性能、制造成本等方面展现出了巨大的潜力。虽然近年来QLED器件在各方面的性能不断得到提升，但无论是在器件效率还是在器件工作稳定性等基本器件性能参数上还与产业化应用的要求有相当的差距，这也大大阻碍了量子点电致发光显示技术的发展和应用。另外，不仅限于QLED器件，在其他领域中，量子点材料相对于传统材料的特性也被逐渐重视，例如光致发光器件、太阳能电池、显示器件、光电探测器、生物探针以及非线性光学器件等等，以下仅以QLED器件为例进行说明。Quantum dots are special materials that are limited to the order of nanometers in three dimensions. This remarkable quantum confinement effect makes quantum dots have many unique nano properties: the emission wavelength is continuously adjustable, and the emission wavelength is narrow. Wide absorption spectrum, high luminous intensity, long fluorescence lifetime and good biocompatibility. These characteristics make quantum dots have broad application prospects in the fields of flat panel display, solid state lighting, photovoltaic solar energy, and biomarkers. Especially in flat panel display applications, Quantum dot light-emitting diodes (QLEDs) based on quantum dot materials have been displaying image quality, device performance, and performance by virtue of the characteristics and optimization of quantum dot nanomaterials. Manufacturing costs and other aspects have shown great potential. Although the performance of QLED devices has been continuously improved in recent years, there are considerable gaps between the performance requirements of industrial devices and the basic device performance parameters such as device efficiency and device operation stability, which also greatly hinders quantum. Development and application of point electroluminescent display technology. In addition, not only QLED devices, but also in other fields, quantum dot materials have been paid more and more attention to the characteristics of traditional materials, such as photoluminescent devices, solar cells, display devices, photodetectors, bioprobes, and nonlinear optics. Etc., the following only describes the QLED device as an example.

虽然量子点作为一种经典的纳米材料已经被研究和开发超过30年，但是利用量子点的优良发光特性并将其作为发光材料应用在QLED器件及相应的显示技术中的研究时间还很短；因此目前绝大部分的QLED器件的开发和研究均是基于已有经典结构体系的量子点材料，相应的量子点材料的筛选和优化的标准还基本是从量子点自身的发光性能例如量子点的发光峰宽、溶液量子产率等出发。将以上量子点直接应用于QLED器件结构中从而获得相应的器件性能结果。Although quantum dots have been researched and developed as a classic nanomaterial for more than 30 years, the research time of using the excellent luminescent properties of quantum dots and applying them as luminescent materials in QLED devices and corresponding display technologies is still short; Therefore, the development of most of the current QLED devices And the research is based on the quantum dot material of the existing classical structure system. The corresponding standard of screening and optimization of the quantum dot material is basically based on the luminescent properties of the quantum dot itself, such as the luminescence peak width of the quantum dot, the solution quantum yield, and the like. . The above quantum dots are directly applied to the QLED device structure to obtain corresponding device performance results.

但QLED器件及相应的显示技术作为一套复杂的光电器件体系，会有诸多方面的因素会影响器件的性能。单从作为核心发光层材料的量子点材料出发，所需权衡的量子点性能指标就会复杂得多。However, QLED devices and corresponding display technologies as a complex optoelectronic device system, there will be many factors that will affect the performance of the device. Starting from the quantum dot material that is the core luminescent layer material, the quantum dot performance metrics that need to be weighed are much more complicated.

首先，量子点在QLED器件中是以量子点发光层固态薄膜的形式存在的，因此量子点材料原本在溶液中所得到的各项发光性能参数在形成固态薄膜后会表现出明显的差异：例如在固态薄膜中发光峰波长会有不同程度的红移(向长波长移动)、发光峰宽度会变大、量子产率会有不同程度的降低，也就是说量子点材料在溶液中的优良发光性能并不能完全被继承至QLED器件的量子点固态薄膜中。因此在设计和优化量子点材料的结构和合成配方时，需同时考虑量子点材料自身的发光性能最优化以及量子点材料在固态薄膜状态下的发光性能继承最大化。First, quantum dots exist in the form of solid-state films of quantum dot luminescent layers in QLED devices. Therefore, the luminescent properties of quantum dot materials originally obtained in solution may show significant differences after forming solid films: for example In the solid film, the luminescence peak wavelength will have different degrees of red shift (moving to long wavelength), the luminescence peak width will become larger, and the quantum yield will be reduced to different extents, that is, the quantum luminescent material has excellent luminescence in solution. Performance is not fully inherited into the quantum dot solid state film of QLED devices. Therefore, in designing and optimizing the structure and synthetic formulation of quantum dot materials, it is necessary to simultaneously consider the optimization of the luminescent properties of the quantum dot material itself and the luminescence inheritance of the quantum dot material in the state of the solid film.

其次，在QLED器件中量子点材料的发光是通过电致激发来实现的，即分别从QLED器件的阳极和阴极通电注入空穴和电子，空穴和电子通过QLED器件中相应功能层的传输在量子点发光层复合后，通过辐射跃迁的方式发射光子即实现发光。从以上过程可以看出，量子点自身的发光性能例如发光效率只是影响上述过程中辐射跃迁的效率，而QLED器件的整体发光效率还会同时受到上述过程中空穴和电子在量子点材料中的电荷注入和传输效率、空穴和电子在量子点材料中的相对电荷平衡、空穴和电子在量子点材料中的复合区域等的影响。因此在设计和优化量子点材料的结构尤其是量子点的精细核壳纳米结构时，还需重点考虑量子点形成固态薄膜以后的电学性能：例如量子点的电荷注入和传导性能、量子点的精细能带结构、量子点的激子寿命等。 Secondly, the luminescence of quantum dot materials in QLED devices is achieved by electro-excitation, that is, energization of holes and electrons from the anode and cathode of the QLED device, respectively, and the transport of holes and electrons through the corresponding functional layers in the QLED device. After the quantum dot luminescent layer is combined, photons are emitted by means of radiation transitions to achieve luminescence. It can be seen from the above process that the luminescent properties of the quantum dots themselves, such as luminescence efficiency, only affect the efficiency of the radiation transition in the above process, and the overall luminescence efficiency of the QLED device is also affected by the charge of holes and electrons in the quantum dot material in the above process. Injection and transport efficiency, relative charge balance of holes and electrons in quantum dot materials, recombination of holes and electrons in quantum dot materials, and the like. Therefore, in designing and optimizing the structure of quantum dot materials, especially the fine core-shell nanostructures of quantum dots, it is also necessary to consider the electrical properties of quantum dots after forming solid films: for example, charge injection and conduction properties of quantum dots, fineness of quantum dots. Energy band structure, exciton lifetime of quantum dots, etc.

最后，考虑到QLED器件及相应显示技术未来将通过极具生产成本优势的溶液法例如喷墨打印法进行制备，因此量子点的材料设计和开发需要考虑量子点溶液的加工性能，例如量子点溶液或打印墨水的可分散溶解性、胶体稳定性、打印成膜性等。同时，量子点材料的开发还要与QLED器件其他功能层材料以及器件的整体制备工艺流程和要求作协同。Finally, considering that QLED devices and corresponding display technologies will be prepared in the future by solution methods such as inkjet printing, which are advantageous in production cost, the material design and development of quantum dots need to consider the processing properties of quantum dot solutions, such as quantum dot solutions. Or the dispersible solubility of the printing ink, the colloidal stability, the print film forming property, and the like. At the same time, the development of quantum dot materials is also coordinated with the other functional layer materials of QLED devices and the overall fabrication process and requirements of the devices.

总之，传统的仅从提升量子点自身发光性能考虑出发的量子点结构设计是无法满足QLED器件及相应显示技术对于量子点材料在光学性能、电学性能、加工性能等多方面的综合要求的。需要针对QLED器件及相应显示技术的要求，对量子点发光材料的精细核壳结构、组分、能级等进行量身定制。In short, the traditional quantum dot structure design, which only considers the improvement of the quantum dot self-luminescence performance, can not meet the comprehensive requirements of QLED devices and corresponding display technologies for the optical properties, electrical properties and processing properties of quantum dot materials. The fine core-shell structure, composition, energy level, etc. of the quantum dot luminescent material need to be tailored to the requirements of the QLED device and the corresponding display technology.

由于量子点的高表面原子比率，未与表面配体(Ligand)形成非共价键(Dangling bond)的原子将以表面缺陷态存在，这种表面缺陷态将会引起非辐射途径的跃迁从而使得量子点的发光量子产率大幅被降低。为解决这一问题，可以在原量子点外层表面生长包含另一种半导体材料的半导体壳层，形成量子点的核壳(core‐shell)结构，可以显著改善量子点的发光性能，同时增加量子点的稳定性。Due to the high surface atomic ratio of quantum dots, atoms that do not form a non-covalent bond with the surface ligand (Ligand) will exist in a surface defect state, which will cause a transition of the non-radiative pathway, thereby The quantum yield of luminescence of quantum dots is greatly reduced. In order to solve this problem, a semiconductor shell layer containing another semiconductor material can be grown on the outer surface of the original quantum dot to form a core-shell structure of the quantum dot, which can significantly improve the luminescent properties of the quantum dot and increase the quantum. Point stability.

可应用于高性能QLED器件开发的量子点材料主要为具有核壳结构的量子点，其核和壳成分分别固定且核壳具有明确边界，例如具有CdSe/ZnS核壳结构的量子点(J.Phys.Chem.,1996,100(2),468–471)、具有CdSe/CdS核壳结构的量子点(J.Am.Chem.Soc.1997,119,(30),7019‐7029)、具有CdS/ZnS核壳结构的量子点、具有CdS/CdSe/CdS核+多层壳层结构的量子点(Patent US 7,919,012 B2)、具有CdSe/CdS/ZnS核+多层壳层结构的量子点(J.Phys.Chem.B,2004,108(49),18826–18831)等。在这些核壳结构的量子点中，通常来说核和壳的组成成分是固定并且不同的，且一般是由一种阳离子和一种阴离子组成的二元化合物体系。在这种结构中，由于核和壳的生长是独立分别进行的，因此核和壳之间的边界是明确，即核和壳可以区分的。这种核壳结构量子点的开发提升了原先单一成分量子点的发光量子效率、单分散性以及量子点稳定性。The quantum dot materials that can be applied to the development of high-performance QLED devices are mainly quantum dots with a core-shell structure, the core and shell components are respectively fixed and the core shell has a clear boundary, such as a quantum dot having a CdSe/ZnS core-shell structure (J. Phys. Chem., 1996, 100(2), 468–471), quantum dots having a CdSe/CdS core-shell structure (J. Am. Chem. Soc. 1997, 119, (30), 7019‐7029), with Quantum dots of CdS/ZnS core-shell structure, quantum dots with CdS/CdSe/CdS core+multilayer shell structure (Patent US 7,919,012 B2), quantum dots with CdSe/CdS/ZnS core+multilayer shell structure J. Phys. Chem. B, 2004, 108 (49), 18826 - 18831) and the like. In the quantum dots of these core-shell structures, the composition of the core and the shell is generally fixed and different, and is generally a binary compound system composed of a cation and an anion. In this structure, since the growth of the core and the shell are independently performed, the boundary between the core and the shell is clear, that is, the core and the shell can be distinguished. The development of such core-shell quantum dots has improved the quantum efficiency, monodispersity, and quantum dot stability of the original single-component quantum dots.

以上所述核壳结构的量子点虽然部分提高了量子点性能，但无论从设计思路还是从优化方案上均还是基于提升量子点自身的发光效率方面考虑，且发光性能还有待提高，另外也未综合考虑半导体器件对于量子点材料的其他方面特殊要求。Although the quantum dots of the core-shell structure described above partially improve the quantum dot performance, both the design idea and the optimization scheme are based on the improvement of the luminous efficiency of the quantum dots themselves, and the luminescence performance needs to be improved, and the Consider the special requirements of semiconductor devices for other aspects of quantum dot materials.

因此，上述技术还有待于改进和发展。Therefore, the above technology has yet to be improved and developed.

发明内容Summary of the invention

鉴于上述现有技术的不足，本发明的目的在于提供一种纳米晶体、制备方法及半导体器件，旨在解决现有的量子点材料其发光性能有待提高、无法满足半导体器件对于量子点材料的要求的问题。In view of the above deficiencies of the prior art, the object of the present invention is to provide a nanocrystal, a preparation method and a semiconductor device, which aim to solve the problem that the existing quantum dot material needs to be improved in luminescent properties and cannot meet the requirements of the semiconductor device for quantum dot materials. The problem.

本发明的技术方案如下：The technical solution of the present invention is as follows:

一种纳米晶体，其中，所述纳米晶体包含S个位于纳米晶体中心的中心结构单元和N个位于纳米晶体中心外并依次排布的环绕结构单元，其中N≥2，S≥1，所述中心结构单元与环绕结构单元均为量子点结构单元；a nanocrystal, wherein the nanocrystal comprises S central structural units located at a center of the nanocrystal and N surrounding structural units located outside the center of the nanocrystal and arranged in sequence, wherein N≥2, S≥1, The central structural unit and the surrounding structural unit are both quantum dot structural units;

所述中心结构单元为径向方向上越向外能级宽度越宽的渐变合金组分结构；The central structural unit is a graded alloy composition structure in which the width of the outer level is wider in the radial direction;

所述N个环绕结构单元由M个第一环绕结构单元以及(N‐M)个第二环绕结构单元组成，所述M个第一环绕结构单元为径向方向上能级宽度一致的均一组分结构，所述(N‐M)个第二环绕结构单元为径向方向上越向外能级宽度越宽的渐变合金组分结构，M≥1；The N surrounding structural units are composed of M first surrounding structural units and (N-M) second surrounding structural units, the M first surrounding structural units being a uniform set of energy levels in the radial direction. a sub-structure, the (N-M) second surrounding structural unit is a graded alloy composition structure having a wider outer-level width in a radial direction, M≥1;

至少有一个第一环绕结构单元位于第二环绕结构单元与中心结构单元之间，相邻的中心结构单元的能级是连续的，相邻的第二环绕结构单元的能级也是连续的。At least one first surrounding structural unit is located between the second surrounding structural unit and the central structural unit, the energy levels of the adjacent central structural units are continuous, and the energy levels of the adjacent second surrounding structural units are also continuous.

所述的纳米晶体，其中，所述中心结构单元为包含II族和VI族元素的渐变合金组分结构；所述第一环绕结构单元为包含II族和VI族元素的均一合金组分结构；且所述第二环绕结构单元为包含II族和VI族元素的渐变合金组分结构。The nanocrystal, wherein the central structural unit is a group II and group VI element a graded alloy component structure; the first surrounding structural unit is a uniform alloy component structure comprising Group II and Group VI elements; and the second surrounding structural unit is a graded alloy component structure comprising Group II and Group VI elements .

所述的纳米晶体，其中，所述中心结构单元的合金组分为Cd_x0Zn_1‐x0Se_y0S_1‐y0，其中0≤x0≤1，0≤y0≤1，并且x0和y0不同时为0和不同时为1。The nanocrystal, wherein the alloy component of the central structural unit is Cd _x0 Zn _1‐x0 Se _y0 S _1‐y0 , where 0≤x0≤1, 0≤y0≤1, and x0 and y0 are different It is 0 and is not 1.

所述的纳米晶体，其中，所述第一环绕结构单元的合金组分为Cd_x1Zn_1‐x1Se_y1S_1‐y1，其中0≤x1≤1，0≤y1≤1，并且x1和y1不同时为0和不同时为1，且x1和y1在相应第一环绕结构单元内为固定值。The nanocrystal, wherein the alloy component of the first surrounding structural unit is Cd _x1 Zn _1‐x1 Se _y1 S _1‐y1 , where 0≤x1≤1, 0≤y1≤1, and x1 and y1 They are not 0 at the same time and 1 at different times, and x1 and y1 are fixed values in the corresponding first surrounding structural unit.

所述的纳米晶体，其中，所述第二环绕结构单元的合金组分为Cd_x2Zn_1‐x2Se_y2S_1‐y2，其中0≤x2≤1，0≤y2≤1，并且x2和y2不同时为0和不同时为1。The nanocrystal, wherein the alloy composition of the second surrounding structural unit is Cd _x2 Zn ₁ -x2 Se _y2 S _1‐y2 , where 0≤x2≤1, 0≤y2≤1, and x2 and y2 It is 0 at different times and 1 at different times.

所述的纳米晶体，其中，所述中心结构单元中，A点的合金组分为Cd_x0 ^AZn_1‐x0 ^ASe_y0 ^AS_1‐y0 ^A和，B点的合金组分为Cd_x0 ^BZn_1‐x0 ^BSe_y0 ^BS_1‐y0 ^B，其中A点相对于B点更靠近纳米晶体中心，且A点和B点的组成满足：_x0 ^A＞_x0 ^B，_y0 ^A＞_y0 ^B。In the nanocrystal, wherein the alloy component of point A in the central structural unit is Cd _x0 ^A Zn _{1 - x0} ^A Se _y0 ^A S _{1 - y0} ^A and the alloy composition of point B is Cd _x0 ^B Zn _1‐x0 ^B Se _y0 ^B S _1‐y0 ^B , where point A is closer to the center of the nanocrystal relative to point B, and the composition of point A and point B satisfies: _x0 ^A > _x0 ^B , _y0 ^A > _y0 ^B .

所述的纳米晶体，其中，所述第二环绕结构单元中，C点的合金组分为Cd_x2 ^CZn_1‐x2 ^CSe_y2 ^CS_1‐y2 ^C，D点的合金组分为Cd_x2 ^DZn_1‐x2 ^DSe_y2 ^DS_1‐y2 ^D；其中C点相对于D点更靠近纳米晶体中心，C点和D点的组成满足：_x2 ^C＞_x2 ^D，_y2 ^C＞_y2 ^D。In the nanocrystal, wherein the alloy component of the C-point in the second surrounding structural unit is Cd _x2 ^C Zn _{1 -x2} ^C Se _y2 ^C S _1‐y2 ^C , and the alloy composition of the D point is Cd _x2 ^D Zn _1‐x2 ^D Se _y2 ^D S _1‐y2 ^D ; where point C is closer to the center of the nanocrystal relative to point D, and the composition of point C and point D satisfies: _x2 ^C > _x2 ^D , _y2 ^C > _y2 ^D .

所述的纳米晶体，其中，所述量子点结构单元包含2‐20层的单原子层，或者所述量子点结构单元包含1‐10层的晶胞层。The nanocrystal, wherein the quantum dot structural unit comprises a 2-20 layer monoatomic layer, or the quantum dot structural unit comprises a 1-10 layer cell layer.

所述的纳米晶体，其中，在径向方向上相邻的渐变合金组分结构的量子点结构单元交界处的两个单原子层之间形成连续合金组分结构，或者在径向方向上相邻的渐变合金组分结构的量子点结构单元交界处的两个晶胞层之间形成连续合金组分结构。The nanocrystal in which a continuous alloy composition structure is formed between two monoatomic layers at a junction of quantum dot structure units adjacent to a graded alloy composition structure in a radial direction, or in a radial direction A continuous alloy composition structure is formed between the two unit cell layers at the junction of the quantum dot structure unit of the adjacent graded alloy composition structure.

所述的纳米晶体，其中，所述第一环绕结构单元和第二环绕结构单元在径向方向上交替分布。The nanocrystal, wherein the first surrounding structural unit and the second surrounding structural unit Alternately distributed in the radial direction.

所述的纳米晶体，其中，处于纳米晶体最外层的环绕结构单元为第二环绕结构单元。The nanocrystal, wherein the surrounding structural unit at the outermost layer of the nanocrystal is a second surrounding structural unit.

所述的纳米晶体，其中，所述纳米晶体的发光峰波长范围为400纳米至700纳米。The nanocrystal, wherein the nanocrystal has an emission peak wavelength ranging from 400 nm to 700 nm.

所述的纳米晶体，其中，所述纳米晶体的发光峰的半高峰宽为12纳米至80纳米。The nanocrystal, wherein a half peak width of the luminescence peak of the nanocrystal is 12 nm to 80 nm.

一种如上所述的纳米晶体的制备方法，其中，包括步骤：A method for preparing a nanocrystal as described above, comprising the steps of:

在预定位置处合成第一种化合物；Synthesizing the first compound at a predetermined position;

在第一种化合物的表面合成第二种化合物，所述第一种化合物与所述第二种化合物的合金组分相同或不同；Forming a second compound on the surface of the first compound, the first compound being the same or different from the alloy composition of the second compound;

使第一种化合物和第二种化合物体之间发生阳离子交换反应形成纳米晶体，所述纳米晶体的发光峰波长出现交替的蓝移和不变。A cation exchange reaction occurs between the first compound and the second compound to form nanocrystals having alternating blue shifts and constant wavelengths of luminescence peaks.

所述的纳米晶体的制备方法，其中，所述第一种化合物和/或所述第二种化合物的阳离子前驱体包括Zn的前驱体，所述Zn的前驱体为二甲基锌、二乙基锌、醋酸锌、乙酰丙酮锌、碘化锌、溴化锌、氯化锌、氟化锌、碳酸锌、氰化锌、硝酸锌、氧化锌、过氧化锌、高氯酸锌、硫酸锌、油酸锌或硬脂酸锌中的至少一种。The method for preparing a nanocrystal, wherein the first compound and/or the cationic precursor of the second compound comprises a precursor of Zn, and the precursor of the Zn is dimethyl zinc, diethyl Zinc, zinc acetate, zinc acetylacetonate, zinc iodide, zinc bromide, zinc chloride, zinc fluoride, zinc carbonate, zinc cyanide, zinc nitrate, zinc oxide, zinc peroxide, zinc perchlorate, zinc sulfate At least one of zinc oleate or zinc stearate.

所述的纳米晶体的制备方法，其中，所述第一种化合物和/或所述第二种化合物的阳离子前驱体包括Cd的前驱体，所述Cd的前驱体为二甲基镉、二乙基镉、醋酸镉、乙酰丙酮镉、碘化镉、溴化镉、氯化镉、氟化镉、碳酸镉、硝酸镉、氧化镉、高氯酸镉、磷酸镉、硫酸镉、油酸镉或硬脂酸镉中的至少一种。The method for preparing a nanocrystal, wherein the first compound and/or the cationic precursor of the second compound comprises a precursor of Cd, and the precursor of the Cd is dimethyl cadmium, diethyl Cadmium, cadmium acetate, cadmium acetylacetonate, cadmium iodide, cadmium bromide, cadmium chloride, cadmium fluoride, cadmium carbonate, cadmium nitrate, cadmium oxide, cadmium perchlorate, cadmium phosphate, cadmium sulfate, cadmium oleate or At least one of cadmium stearate.

所述的纳米晶体的制备方法，其中，所述第一种化合物和/或所述第二种化合物的阴离子前驱体包括Se的前驱体，所述Se的前驱体为Se‐TOP、Se‐TBP、Se‐TPP、Se‐ODE、Se‐OA、Se‐ODA、Se‐TOA、Se‐ODPA或Se‐OLA中的至少一种。The method for preparing a nanocrystal, wherein the anion precursor of the first compound and/or the second compound comprises a precursor of Se, and the precursor of the Se is Se‐TOP, Se‐TBP , Se‐TPP, Se‐ODE, Se‐OA, Se‐ODA, Se‐TOA, Se‐ODPA or Se‐OLA At least one of them.

所述的纳米晶体的制备方法，其中，所述第一种化合物和/或所述第二种化合物的阴离子前驱体包括S的前驱体，所述S的前驱体为S‐TOP、S‐TBP、S‐TPP、S‐ODE、S‐OA、S‐ODA、S‐TOA、S‐ODPA、S‐OLA或烷基硫醇中的至少一种。The method for preparing a nanocrystal, wherein the anion precursor of the first compound and/or the second compound comprises a precursor of S, and the precursor of the S is S-TOP, S-TBP At least one of S-TPP, S-ODE, S-OA, S-ODA, S-TOA, S-ODPA, S-OLA or alkyl mercaptan.

所述的纳米晶体的制备方法，其中，所述第一种化合物和/或第二种化合物的阴离子前驱体包括Te的前驱体，所述Te的前驱体为Te‐TOP、Te‐TBP、Te‐TPP、Te‐ODE、Te‐OA、Te‐ODA、Te‐TOA、Te‐ODPA或Te‐OLA中的至少一种。The method for preparing a nanocrystal, wherein the anion precursor of the first compound and/or the second compound comprises a precursor of Te, and the precursor of the Te is Te‐TOP, Te‐TBP, Te At least one of ‐TPP, Te‐ODE, Te‐OA, Te‐ODA, Te‐TOA, Te‐ODPA, or Te‐OLA.

所述的纳米晶体的制备方法，其中，在加热条件下使第一种化合物和第二种化合物体之间发生阳离子交换反应。The method for producing a nanocrystal, wherein a cation exchange reaction occurs between the first compound and the second compound under heating.

所述的纳米晶体的制备方法，其中，加热温度在100℃至400℃之间。The method for preparing the nanocrystal, wherein the heating temperature is between 100 ° C and 400 ° C.

所述的纳米晶体的制备方法，其中，加热时间在2s至24h之间。The method for preparing the nanocrystal, wherein the heating time is between 2 s and 24 h.

所述的纳米晶体的制备方法，其中，在合成第一种化合物时，阳离子前驱体与阴离子前驱体的摩尔比为100:1到1:50之间。The method for preparing the nanocrystal, wherein, in synthesizing the first compound, the molar ratio of the cationic precursor to the anionic precursor is between 100:1 and 1:50.

所述的纳米晶体的制备方法，其中，在合成第二种化合物时，阳离子前驱体与阴离子前驱体的摩尔比为100:1到1:50之间。The method for preparing the nanocrystal, wherein, in synthesizing the second compound, the molar ratio of the cationic precursor to the anionic precursor is between 100:1 and 1:50.

一种半导体器件，其中，包括如上任一项所述的纳米晶体。A semiconductor device comprising the nanocrystal of any of the above.

所述的半导体器件，其中，所述半导体器件为电致发光器件、光致发光器件、太阳能电池、显示器件、光电探测器、生物探针以及非线性光学器件中的任意一种。The semiconductor device, wherein the semiconductor device is any one of an electroluminescent device, a photoluminescence device, a solar cell, a display device, a photodetector, a bioprobe, and a nonlinear optical device.

有益效果：本发明提供了一种具有从内到外沿径向方向的合金组分的新型纳米晶体，其不仅实现了更高效的发光效率，同时也更能满足半导体器件及相应显示技术对纳米晶体的综合性能要求，是一种适合半导体器件及显示技术的理想纳米晶体。 Advantageous Effects: The present invention provides a novel nanocrystal having an alloy composition from the inside to the outside in a radial direction, which not only achieves more efficient luminous efficiency, but also satisfies semiconductor devices and corresponding display technologies for nanometers. The comprehensive performance requirements of the crystal are an ideal nanocrystal suitable for semiconductor devices and display technologies.

附图说明DRAWINGS

图1为本发明一种纳米晶体较佳实施例的能级结构曲线。1 is a graph showing the energy level structure of a preferred embodiment of a nanocrystal of the present invention.

图2为本发明实施例13中量子点发光二极管的结构示意图。2 is a schematic structural view of a quantum dot light emitting diode according to Embodiment 13 of the present invention.

图3为本发明实施例14中量子点发光二极管的结构示意图。3 is a schematic structural view of a quantum dot light emitting diode according to Embodiment 14 of the present invention.

图4为本发明实施例15中量子点发光二极管的结构示意图。4 is a schematic structural view of a quantum dot light emitting diode according to Embodiment 15 of the present invention.

图5为本发明实施例16中量子点发光二极管的结构示意图。FIG. 5 is a schematic structural view of a quantum dot light emitting diode according to Embodiment 16 of the present invention.

图6为本发明实施例17中量子点发光二极管的结构示意图。FIG. 6 is a schematic structural view of a quantum dot light emitting diode according to Embodiment 17 of the present invention.

图7为本发明实施例18中量子点发光二极管的结构示意图。FIG. 7 is a schematic structural view of a quantum dot light emitting diode according to Embodiment 18 of the present invention.

具体实施方式detailed description

本发明提供一种纳米晶体、制备方法及半导体器件，为使本发明的目的、技术方案及效果更加清楚、明确，以下对本发明进一步详细说明。应当理解，此处所描述的具体实施例仅仅用以解释本发明，并不用于限定本发明。The present invention provides a nanocrystal, a preparation method, and a semiconductor device. The present invention will be further described in detail below in order to make the objects, technical solutions and effects of the present invention more clear and clear. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

本发明所提供的纳米晶体，包含S个位于纳米晶体中心的中心结构单元和N个位于纳米晶体中心外并依次排布的环绕结构单元，其中N≥2，S≥1，所述中心结构单元与环绕结构单元均为量子点结构单元；The nanocrystal provided by the invention comprises S central structural units located at the center of the nanocrystal and N surrounding structural units located outside the center of the nanocrystal and arranged in sequence, wherein N≥2, S≥1, the central structural unit And the surrounding structural unit are both quantum dot structural units;

所述N个环绕结构单元由M个第一环绕结构单元以及(N‐M)个第二环绕结构单元组成，所述M个第一环绕结构单元为径向方向上能级宽度一致的均一组分结构，所述(N‐M)个第二环绕结构单元为径向方向上越向外能级宽度越宽的渐变合金组分结构，M≥1；此处的径向方向是指从纳米晶体的中心向外的方向，例如假设本发明的纳米晶体为球形或类似球形结构，那么该径向方向即指沿半径的方向，纳米晶体的中心即指其物理结构的中心，纳米晶体的表面即指其物理结构的表面。 The N surrounding structural units are composed of M first surrounding structural units and (N-M) second surrounding structural units, the M first surrounding structural units being a uniform set of energy levels in the radial direction. a sub-structure, wherein the (N-M) second surrounding structural units are graded alloy composition structures having a wider outer-level width in the radial direction, M≥1; wherein the radial direction refers to the nanocrystals The center outward direction, for example, assuming that the nanocrystal of the present invention is spherical or a spherical structure, then the radial direction means the direction along the radius, the center of the nanocrystal refers to the center of the physical structure, and the surface of the nanocrystal is Refers to the surface of its physical structure.

至少有一个第一环绕结构单元位于第二环绕结构单元与中心结构单元之间，且相邻的中心结构单元的能级是连续的，相邻的第二环绕结构单元的能级也是连续的。本发明中的纳米晶体，各个相邻的渐变合金组分结构的量子点结构单元的能级是连续的(即相邻的中心结构单元的能级是连续的，同时相邻的第二环绕结构单元的能级也是连续的)，即各个相邻的渐变合金组分结构的量子点结构单元的能级宽度具有连续变化的特点，而非突变结构，这种特性更有利于实现高的发光效率。At least one first surrounding structural unit is located between the second surrounding structural unit and the central structural unit, and the energy levels of the adjacent central structural units are continuous, and the energy levels of the adjacent second surrounding structural units are also continuous. In the nanocrystal of the present invention, the energy levels of the quantum dot structural units of each adjacent graded alloy component structure are continuous (ie, the energy levels of adjacent central structural units are continuous while the adjacent second surrounding structure The energy level of the unit is also continuous), that is, the energy level width of the quantum dot structural unit of each adjacent graded alloy component structure has a continuous change characteristic, rather than a mutated structure, which is more favorable for achieving high luminous efficiency. .

本发明中的纳米晶体，其能级结构如图1所示。即所述的纳米晶体中，其量子点结构单元的分布从内到外是中心结构单元和环绕结构单元，其中中心结构单元的数量可以是大于等于1，当有多个中心结构单元时，各中心结构单元沿着径向方向依次排布，且各中心结构单元均为径向方向上越向外能级宽度越宽的渐变合金组分结构。在具体实施例中称图1的能级结构为量子阱能级结构。The nanocrystal of the present invention has an energy level structure as shown in FIG. That is, in the nanocrystal, the distribution of quantum dot structural units from the inside to the outside is a central structural unit and a surrounding structural unit, wherein the number of central structural units may be greater than or equal to 1, when there are multiple central structural units, each The central structural units are sequentially arranged in the radial direction, and each of the central structural units is a graded alloy composition structure in which the width of the outer level is wider in the radial direction. The energy level structure of Figure 1 is referred to as a quantum well level structure in a particular embodiment.

所述的第一环绕结构单元具有M个，其中的M≥1，也即第一环绕结构单元的数量也可以是大于等于1，且各第一环绕结构单元均优选为径向方向上能级宽度一致的均一合金组分结构，所述第一环绕结构单元也可以是非合金组分结构，即所述第一环绕结构单元可以是合金组分结构或非合金组分结构，但本发明中，所述第一环绕结构单元优选为合金组分结构。The first surrounding structural unit has M, wherein M≥1, that is, the number of the first surrounding structural units may also be greater than or equal to 1, and each of the first surrounding structural units is preferably an energy level in a radial direction. a uniformly uniform uniform alloy composition structure, the first surrounding structural unit may also be a non-alloy component structure, that is, the first surrounding structural unit may be an alloy component structure or a non-alloy component structure, but in the present invention, The first surrounding structural unit is preferably an alloy component structure.

所述的第二环绕结构单元具有N个，其中的N≥1，也即第二环绕结构单元的数量也可以是大于等于1，且各第二环绕结构单元均为径向方向上越向外能级宽度越宽的渐变合金组分结构。The second surrounding structural unit has N, wherein N≥1, that is, the number of the second surrounding structural unit may also be greater than or equal to 1, and each of the second surrounding structural units is radially outward. The graded alloy component structure has a wider width.

在本发明中，所述的第一环绕结构单元与第二环绕结构单元优选是交替分布的，也就是说，当第一环绕结构单元有多个时，那么同时第二环绕结构单元也是同时有多个，这样量子点的能级结构从整体上形成台阶式的结构，当然也可以以单元组的形式交替分布，例如在纳米晶体中，在径向方向上从中心到表面，依次为中心结构单元、第一组第一环绕结构单元、第一组第二环绕结构单元、第二组第一环绕结构单元、第二组第二环绕结构单元、第三组第一环绕结构单元、第三组第二环绕结构单元…依次类推，而每一组的第一环绕结构单元和每一组的第二环绕结构单元中，相应结构单元的数量可以相同也可以不同，且每一组中，相邻的第二环绕结构单元其能级是连续的，其中的中心结构单元可以有多个，并且依次分布，且相邻中心结构单元的能级是连续的。进一步，处于最外层的环绕结构单元为第二环绕结构单元，即纳米晶体中的最外层其能级宽度是越向外越宽的。In the present invention, the first surrounding structural unit and the second surrounding structural unit are preferably alternately distributed, that is, when there are multiple first surrounding structural units, then the second surrounding structural unit is also simultaneously a plurality of such quantum layer energy level structures form a stepped structure as a whole, and may of course be alternately distributed in the form of a unit group, for example, in a nanocrystal, in a radial direction from the center to the surface, in turn, a central structure Unit, first set of first surrounding structural units, a first set of second surround structure units, a second set of first surround structure units, a second set of second surround structure units, a third set of first surround structure units, a third set of second surround structure units, and so on, and each In a group of first surrounding structural units and each group of second surrounding structural units, the number of corresponding structural units may be the same or different, and in each group, adjacent second surrounding structural units have continuous energy levels. There may be more than one central structural unit, and are sequentially distributed, and the energy levels of adjacent central structural units are continuous. Further, the surrounding structural unit at the outermost layer is a second surrounding structural unit, that is, the outermost layer of the nanocrystal has an energy level width that is wider toward the outside.

进一步，所述中心结构单元、第一环绕结构单元和第二环绕结构单元均包含II族和VI族元素，即所述中心结构单元是包含II族和VI族元素的渐变合金组分结构；所述第一环绕结构单元是包含II族和VI族元素的均一合金组分结构；所述第二环绕结构单元是包含II族和VI族元素的渐变合金组分结构。所述II族元素包括但不限于Zn、Cd、Hg、Cn等。所述VI族元素包括但不限于O、S、Se、Te、Po、Lv等。Further, the central structural unit, the first surrounding structural unit, and the second surrounding structural unit each comprise a Group II and a Group VI element, that is, the central structural unit is a graded alloy component structure comprising Group II and Group VI elements; The first surrounding structural unit is a uniform alloy component structure comprising Group II and Group VI elements; the second surrounding structural unit is a graded alloy component structure comprising Group II and Group VI elements. The Group II elements include, but are not limited to, Zn, Cd, Hg, Cn, and the like. The Group VI elements include, but are not limited to, O, S, Se, Te, Po, Lv, and the like.

进一步，所述中心结构单元的合金组分为Cd_x0Zn_1‐x0Se_y0S_1‐y0，其中0≤x0≤1，0≤y0≤1，并且x0和y0不同时为0和不同时为1。例如某一点处的合金组分为Cd_0.5Zn_0.5Se_0.5S_0.5，而另一点的合金组分为Cd_0.3Zn_0.7Se_0.4S_0.6。Further, the alloy component of the central structural unit is Cd _x0 Zn _1‐x0 Se _y0 S _1‐y0 , where 0≤x0≤1, 0≤y0≤1, and x0 and y0 are not 0 at the same time and are not simultaneously 1. For example, the alloy composition at a certain point is Cd _0.5 Zn _0.5 Se _0.5 S _0.5 , and the alloy composition at another point is Cd _0.3 Zn _0.7 Se _0.4 S _0.6 .

进一步，所述第一环绕结构单元的合金组分为Cd_x1Zn_1‐x1Se_y1S_1‐y1，其中0≤x1≤1，0≤y1≤1，并且x1和y1不同时为0和不同时为1，且x1和y1在相应第一环绕结构单元内为固定值。例如某一点的合金组分为Cd_0.5Zn_0.5Se_0.5S_0.5，而另一点的合金组分也应为Cd_0.5Zn_0.5Se_0.5S_0.5。又例如第一环绕结构单元的某一点的合金组分为Cd_0.7Zn_0.3S，而该第一环绕结构单元内另一点的合金组分也应为Cd_0.7Zn_0.3S；又例如第一环绕结构单元的某一点的合金组分为CdSe，而该第一环绕结构单元内另一点的合金组分也应为CdSe。Further, the alloy composition of the first surrounding structural unit is Cd _x1 Zn ₁ -x1 Se _y1 S _1‐y1 , where 0≤x1≤1, 0≤y1≤1, and x1 and y1 are not 0 and not At the same time, it is 1, and x1 and y1 are fixed values in the corresponding first surrounding structural unit. For example, a point alloy component _{_{_{_{Cd 0.5 Zn 0.5 Se 0.5 S 0.5}}}} , and the alloy components should also be another point _{_{_{_{Cd 0.5 Zn 0.5 Se 0.5 S 0.5}}}} . For another example, the alloy composition of a certain point of the first surrounding structural unit is Cd _0.7 Zn _0.3 S, and the alloy composition of another point in the first surrounding structural unit should also be Cd _0.7 Zn _0.3 S; for example, the first surrounding structure The alloy component at one point of the unit is CdSe, and the alloy composition at another point in the first surrounding structural unit should also be CdSe.

进一步，所述第二环绕结构单元的合金组分组成为Cd_x2Zn_1‐x2Se_y2S_1‐y2，其中0≤x2≤1，0≤y2≤1，并且x2和y2不同时为0和不同时为1。例如某一点的合金组分为Cd_0.5Zn_0.5Se_0.5S_0.5，而另一点的合金组分为Cd_0.3Zn_0.7Se_0.4S_0.6。 Further, the alloy composition of the second surrounding structural unit is Cd _x2 Zn ₁ -x2 Se _y2 S _1‐y2 , where 0≤x2≤1, 0≤y2≤1, and x2 and y2 are not 0 and not at the same time. At the same time it is 1. For example, the alloy composition at a certain point is Cd _0.5 Zn _0.5 Se _0.5 S _0.5 , and the alloy composition at another point is Cd _0.3 Zn _0.7 Se _0.4 S _0.6 .

进一步，所述中心结构单元中，A点的合金组分为Cd_x0 ^AZn_1‐x0 ^ASe_y0 ^AS_1‐y0 ^A，B点的合金组成为Cd_x0 ^BZn_1‐x0 ^BSe_y0 ^BS_1‐y0 ^B，其中A点相对于B点更靠近纳米晶体中心，且A点和B点的组成满足：_x0 ^A＞_x0 ^B，_y0 ^A＞_y0 ^B。也就是说，对于中心结构单元中的任意两点A点和B点，且A点相对于B点更靠近纳米晶体中心，那么_x0 ^A＞_x0 ^B，_y0 ^A＞_y0 ^B，即A点的Cd含量大于B点的Cd含量，A点的Zn含量小于B点的Zn含量，A点的Se含量大于B点的Se含量，A点的S含量小于B点的S含量。这样，在中心结构单元中，就在径向方向上形成了渐变结构，并且由于在径向方向上，越向外(即远离纳米晶体中心)则Cd和Se含量越低，Zn和S含量越高，那么根据这几种元素的特性，其能级宽度将会越宽。Further, in the central structural unit, the alloy composition of point ^A is Cd _x0 ^A Zn _{1 - x0} ^A Se _y0 ^A S _{1 - y0} ^A , and the alloy composition of point B is Cd _x0 ^B Zn _{1 - x0} ^B Se _y0 ^B S _1‐y0 ^B , where point A is closer to the center of the nanocrystal relative to point B, and the composition of points A and B satisfies: _x0 ^A > _x0 ^B , _y0 ^A > _y0 ^B . That is, for any two points A and B in the central structural unit, and point A is closer to the center of the nanocrystal relative to point B, then _x0 ^A > _x0 ^B , _y0 ^A > _y0 ^B , ie Cd of point A The content of Cd above the B point, the Zn content at point A is less than the Zn content at point B, the Se content at point A is greater than the Se content at point B, and the S content at point A is less than the S content at point B. Thus, in the central structural unit, a gradual structure is formed in the radial direction, and the lower the Cd and Se contents, the lower the content of Zn and S is due to the outward direction (i.e., away from the center of the nanocrystal) in the radial direction. High, then according to the characteristics of these elements, the width of the energy level will be wider.

进一步，所述第二环绕结构单元中，C点的合金组分为Cd_x2 ^CZn_1‐x2 ^CSe_y2 ^CS_1‐y2 ^C，D点的合金组分为Cd_x2 ^DZn_1‐x2 ^DSe_y2 ^DS_1‐y2 ^D；其中C点相对于D点更靠近纳米晶体中心，C点和D点的组成满足：_x2 ^C＞_x2 ^D，_y2 ^C＞_y2 ^D。也就是说，对于第二环绕结构单元中的任意两点C点和D点，且C点相对于D点更靠近纳米晶体中心，那么_x2 ^C＞_x2 ^D，_y2 ^C＞_y2 ^D，即C点的Cd含量大于D点的Cd含量，C点的Zn含量小于D点的Zn含量，C点的Se含量大于D点的Se含量，C点的S含量小于D点的S含量。这样，在第二环绕结构单元中，就在径向方向上形成了渐变结构，并且由于在径向方向上，越向外(即远离纳米晶体中心)则Cd和Se含量越低，Zn和S含量越高，那么根据这几种元素的特性，其能级宽度将会越宽。Further, in the second surrounding structural unit, the alloy composition of the C point is Cd _x2 ^C Zn _1‐x2 ^C Se _y2 ^C S _1‐y2 ^C , and the alloy composition of the D point is Cd _x2 ^D Zn _1‐x2 ^D Se _y2 ^D S _1‐y2 ^D ; where point C is closer to the center of the nanocrystal relative to point D, and the composition of point C and point D satisfies: _x2 ^C > _x2 ^D , _y2 ^C > _y2 ^D . That is, for any two points C and D in the second surrounding structural unit, and point C is closer to the center of the nanocrystal relative to point D, then _x2 ^C > _x2 ^D , _y2 ^C > _y2 ^D , ie point C The Cd content is greater than the Cd content at point D, the Zn content at point C is less than the Zn content at point D, the Se content at point C is greater than the Se content at point D, and the S content at point C is less than the S content at point D. Thus, in the second surrounding structural unit, a gradual structure is formed in the radial direction, and since the radial direction is outward (i.e., away from the center of the nanocrystal), the Cd and Se contents are lower, Zn and S. The higher the content, the wider the level of the energy level will be based on the characteristics of these elements.

进一步，所述中心结构单元、所述第一环绕结构单元和第二环绕结构单元均包含2‐20层的单原子层。即，每一个量子点结构单元都包含2‐20层的单原子层。优选的为2个单原子层至5个单原子层，优选的层数能够保证量子点实现良好的发光量子产率以及高效的电荷注入效率。Further, the central structural unit, the first surrounding structural unit, and the second surrounding structural unit each comprise a 2-20 layer monoatomic layer. That is, each quantum dot structural unit contains a 2-20 layer of a single atomic layer. Preferred are 2 monoatomic layers to 5 monoatomic layers. The preferred number of layers ensures that the quantum dots achieve good luminescence quantum yield and efficient charge injection efficiency.

进一步的，中心结构单元、第一环绕结构单元和第二环绕结构单元中的每一单原子层均为最小结构单元，即每一层的单一原子层其合金组分均是固定的，而相邻的两个单原子层之间可能会形成渐变合金组分结构，例如在中心结构单元和第二环绕结构单元中，远离纳米晶体中心的单原子层，其Cd和Se含量低，Zn和S含量高，靠近纳米晶体中心的单原子层，其Cd和Se含量低，Zn和S含量高，从而形成渐变合金组分结构。但在每一第一环绕结构单元中，每一层的单原子层其合金组分相同，以形成均一合金组分结构。Further, each of the central structural unit, the first surrounding structural unit, and the second surrounding structural unit is a minimum structural unit, that is, a single atomic layer of each layer has an alloy composition It is fixed, and a graded alloy composition structure may be formed between adjacent two monoatomic layers, for example, in the central structural unit and the second surrounding structural unit, a single atomic layer away from the center of the nanocrystal, and its Cd and Se The content is low, the content of Zn and S is high, and the single atomic layer near the center of the nanocrystal has a low Cd and Se content, and a high content of Zn and S, thereby forming a graded alloy composition structure. However, in each of the first surrounding structural units, the monoatomic layer of each layer has the same alloy composition to form a uniform alloy composition structure.

或者，所述中心结构单元、所述第一环绕结构单元和第二环绕结构单元均包含1‐10层的晶胞层，即每一量子点结构单元均包含1‐10层的晶胞层，例如包含2‐5层的晶胞层。晶胞层为最小结构单元，即每一层的晶胞层其合金组分均是固定的，即每一晶胞层内具有相同晶格参数和元素。每一量子点结构单元均为晶胞层连续连接而构成的封闭晶胞曲面。Alternatively, the central structural unit, the first surrounding structural unit, and the second surrounding structural unit each comprise a 1-10 layer of a cell layer, that is, each quantum dot structural unit comprises a 1-10 layer of a cell layer. For example, a cell layer comprising 2-5 layers. The cell layer is the smallest structural unit, that is, the cell layer of each layer has its alloy composition fixed, that is, the same lattice parameter and element in each cell layer. Each quantum dot structural unit is a closed unit cell curved surface formed by continuous connection of the unit cell layers.

优选的，在径向方向上相邻的渐变合金组分结构的量子点结构单元交界的两个单原子层之间形成连续合金组分结构，即，两个渐变合金组分结构的量子点结构单元交界处的两个单原子层之间是连续合金组分结构，也即其能级宽度也是渐变的，而不是突变的。或者，在径向方向上相邻的渐变合金组分结构的量子点结构单元交界处的两个晶胞层之间形成连续合金组分结构。上述提到的相邻的渐变合金组分结构的量子点结构单元即为相邻的中心结构单元，和相邻的第二环绕结构单元。Preferably, a continuous alloy composition structure is formed between two monoatomic layers at the junction of quantum dot structure units of a graded alloy composition structure adjacent in a radial direction, that is, a quantum dot structure of two graded alloy composition structures Between the two monoatomic layers at the cell junction is a continuous alloy composition structure, that is, its energy level width is also gradual rather than abrupt. Alternatively, a continuous alloy composition structure is formed between the two unit cell layers at the junction of the quantum dot structure unit of the graded alloy composition structure adjacent in the radial direction. The quantum dot structural units of the adjacent graded alloy composition structures mentioned above are adjacent central structural units, and adjacent second surrounding structural units.

也就是说，本发明的纳米晶体，在相邻的中心结构单元之间和相邻的第二环绕结构单元之间均具有从内到外沿径向方向的连续合金组分。这种量子点结构在组成成分上和能级分布上的特点，相对于具有明确边界的量子点核和壳的关系，本发明的纳米晶体不仅有利于实现更高效的发光效率，同时也更能满足半导体器件及相应显示技术对纳米晶体的综合性能要求，是一种适合半导体器件及显示技术的理想量子点发光材料。That is, the nanocrystal of the present invention has a continuous alloy composition in the radial direction from the inside to the outside between adjacent central structural units and between adjacent second surrounding structural units. The characteristics of the quantum dot structure in terms of composition and energy level distribution, the nanocrystal of the present invention is not only beneficial for achieving more efficient luminous efficiency, but also more capable of being related to the relationship between the quantum dot core and the shell having a clear boundary. It satisfies the comprehensive performance requirements of semiconductor devices and corresponding display technologies for nanocrystals, and is an ideal quantum dot luminescent material suitable for semiconductor devices and display technologies.

本发明采用上述结构的纳米晶体，能够实现的发光量子产率范围为1％至100％，优选的发光量子产率范围为30％至100％，优选的发光量子产率范围内能够保证量子点的良好应用性。The present invention adopts the nanocrystal of the above structure, and the luminescence quantum yield which can be achieved ranges from 1% to 100%, and the preferred luminescence quantum yield ranges from 30% to 100%, and the preferred luminescence quantum yield The good applicability of quantum dots can be guaranteed within the range.

本发明采用上述结构的纳米晶体，能够实现的发光峰波长范围为400纳米至700纳米，优选的发光峰波长范围为430纳米至660纳米，优选的量子点发光峰波长范围能够保证纳米晶体在此范围内实现大于30％的发光量子产率。The nanocrystal of the above structure can realize the luminescence peak wavelength range of 400 nm to 700 nm, and the preferred luminescence peak wavelength range is 430 nm to 660 nm, and the preferred quantum dot luminescence peak wavelength range can ensure the nanocrystal is here. A luminescence quantum yield of greater than 30% is achieved in the range.

本发明中，所述纳米晶体的发光峰的半高峰宽为12纳米至80纳米。In the present invention, the half peak width of the luminescence peak of the nanocrystal is from 12 nm to 80 nm.

本发明所提供的纳米晶体具有如下有益效果：第一，有助于最大程度上减少不同合金组分的量子点晶体间的晶格张力并缓解晶格失配，从而减少了界面缺陷的形成，提高了量子点的发光效率。第二，本发明所提供的量子点材料所形成的能级结构更有利于对量子点中电子云的有效束缚，大大减少电子云向量子点表面的扩散几率，从而极大地抑制了量子点无辐射跃迁的俄歇复合损失，减少量子点闪烁并提高量子点发光效率。第三，本发明所提供的量子点材料所形成的能级结构更有利于提高半导体器件中量子点发光层电荷的注入效率和传输效率；同时能够有效避免电荷的聚集以及由此产生的激子淬灭。第四，本发明所提供的量子点材料所形成的易于控制的多样性能级结构能够充分满足并配合器件中其他功能层的能级结构，以实现器件整体能级结构的匹配，从而有助于实现高效的半导体器件。The nanocrystals provided by the invention have the following beneficial effects: firstly, it helps to minimize the lattice tension between quantum dot crystals of different alloy compositions and alleviate lattice mismatch, thereby reducing the formation of interface defects. The luminous efficiency of quantum dots is improved. Secondly, the energy level structure formed by the quantum dot material provided by the invention is more favorable for the effective binding of the electron cloud in the quantum dot, and greatly reduces the probability of diffusion of the surface of the electron cloud vector sub-point, thereby greatly suppressing the quantum dot without The Auger recombination loss of the radiation transition reduces the quantum dot flicker and improves the luminous efficiency of the quantum dot. Thirdly, the energy level structure formed by the quantum dot material provided by the invention is more favorable for improving the injection efficiency and transmission efficiency of the quantum dot light-emitting layer charge in the semiconductor device; and at the same time, the charge accumulation and the resulting exciton can be effectively avoided. Quenched. Fourth, the easily controllable multi-level structure formed by the quantum dot material provided by the present invention can fully satisfy and match the energy level structure of other functional layers in the device, so as to achieve matching of the overall energy level structure of the device, thereby contributing to Achieve efficient semiconductor devices.

本发明还提供一种如上所述的纳米晶体的制备方法，其包括步骤：The invention also provides a method for preparing nanocrystals as described above, comprising the steps of:

本发明的制备方法将量子点SILAR合成法结合量子点一步合成法生成量子点，具体为利用量子点SILAR合成法精确控制量子点逐层生长以及利用量子点一步合成法形成渐变组分过渡壳。即在预定位置处先后形成两层具有不同合金组分的化合物薄层，通过使两层化合物之间发生阳离子交换反应，从而实现在预定位置处的合金组分分布。重复以上过程可以不断实现在径向方向预定位置处的合金组分分布。The preparation method of the invention combines the quantum dot SILAR synthesis method with the quantum dot one-step synthesis method to generate quantum dots, specifically, the quantum dot SILAR synthesis method is used to precisely control the quantum dot layer-by-layer growth and the quantum dot one-step synthesis method is used to form the graded component transition shell. That is, two layers are formed one after another at the predetermined position. A thin layer of a compound having different alloy compositions achieves a distribution of alloy components at a predetermined position by causing a cation exchange reaction between the two layers of the compound. Repeating the above process can continuously achieve the distribution of the alloy composition at a predetermined position in the radial direction.

所述的第一种化合物和第二种化合物可以是二元或者二元以上化合物。The first compound and the second compound may be binary or binary compounds.

所述纳米晶体的发光峰波长出现交替的蓝移和不变。出现蓝移代表发光峰向短波方向移动，能级宽度变宽，出现红移代表发光峰向长波方向移动，能级宽度变窄，若发光峰波长不变代表则代表能级宽度不变。出现交替的蓝移和不变则代表能级宽度是交替变化的，即如图1所示，在量子点径向方向上，在第一区间(即中心结构单元所在区间)内能级宽度变宽(蓝移)，在第二区间(即第一环绕结构单元所在区间)内能级宽度不变(不变)，在第三区间(即第二环绕结构单元所在区间)内能级宽度变宽(蓝移)。The wavelength of the luminescence peak of the nanocrystals appears alternating blue shift and constant. The blue shift indicates that the illuminating peak shifts toward the short-wave direction, and the energy level width becomes wider. The red shift indicates that the illuminating peak shifts toward the long-wave direction, and the energy level width is narrowed. If the illuminating peak wavelength does not change, the energy level width is constant. The alternating blue shift and invariance indicate that the energy level width is alternated, that is, as shown in Fig. 1, in the radial direction of the quantum dot, the energy level width changes in the first interval (ie, the interval in which the central structural unit is located). Width (blue shift), the energy level width is constant (invariant) in the second interval (ie, the interval in which the first surrounding structural unit is located), and the energy level width is changed in the third interval (ie, the interval in which the second surrounding structural unit is located) Wide (blue shift).

所述第一种化合物和/或所述第二种化合物的阳离子前驱体包括：Zn的前驱体，所述Zn的前驱体为二甲基锌(dimethyl Zinc)、二乙基锌(diethyl Zinc)、醋酸锌(Zinc acetate)、乙酰丙酮锌(Zinc acetylacetonate)、碘化锌(Zinc iodide)、溴化锌(Zinc bromide)、氯化锌(Zinc chloride)、氟化锌(Zinc fluoride)、碳酸锌(Zinc carbonate)、氰化锌(Zinc cyanide)、硝酸锌(Zinc nitrate)、氧化锌(Zinc oxide)、过氧化锌(Zinc peroxide)、高氯酸锌(Zinc perchlorate)、硫酸锌(Zinc sulfate)、油酸锌(Zinc oleate)或硬脂酸锌(Zinc stearate)等中的至少一种，但不限于此。The cation precursor of the first compound and/or the second compound includes: a precursor of Zn, and the precursor of the Zn is dimethyl Zinc, diethyl zinc (diethyl Zinc) , Zinc acetate, Zinc acetylacetonate, Zinc iodide, Zinc bromide, Zinc chloride, Zinc fluoride, Zinc carbonate (Zinc carbonate), Zinc cyanide, Zinc nitrate, Zinc oxide, Zinc peroxide, Zinc perchlorate, Zinc sulfate At least one of Zinc oleate or Zinc stearate, etc., but is not limited thereto.

所述第一种化合物和/或所述第二种化合物的阳离子前驱体包括Cd的前驱体，所述Cd的前驱体为二甲基镉(dimethyl cadmium)、二乙基镉(diethyl cadmium)、醋酸镉(cadmium acetate)、乙酰丙酮镉(cadmium acetylacetonate)、碘化镉(cadmium iodide)、溴化镉(cadmium bromide)、氯化镉(cadmium chloride)、氟化镉(cadmium fluoride)、碳酸镉(cadmium carbonate)、硝酸镉(cadmium nitrate)、氧化镉(cadmium oxide)、高氯酸镉(cadmium perchlorate)、磷酸镉(cadmium phosphide)、硫酸镉(cadmium sulfate)、油酸镉(cadmium oleate)或硬脂酸镉(cadmium stearate)等中的至少一种，但不限于此。The cationic precursor of the first compound and/or the second compound includes a precursor of Cd, and the precursor of the Cd is dimethyl cadmium, diethyl cadmium, Cadmium acetate, cadmium acetylacetonate, cadmium iodide, cadmium bromide, cadmium chloride, cadmium fluoride, cadmium carbonate Cadmium carbonate), cadmium nitrate, cadmium oxide, cadmium perchlorate, cadmium phosphide, cadmium cadmium At least one of sulfate, cadmium oleate or cadmium stearate, etc., but is not limited thereto.

所述第一种化合物和/或第二种化合物的阴离子前驱体包括Se的前驱体，例如Se与一些有机物任意组合所形成的化合物，具体可以是Se‐TOP(selenium‐trioctylphosphine)、Se‐TBP(selenium‐tributylphosphine)、Se‐TPP(selenium‐triphenylphosphine)、Se‐ODE(selenium‐1‐octadecene)、Se‐OA(selenium‐oleic acid)、Se‐ODA(selenium‐octadecylamine)、Se‐TOA(selenium‐trioctylamine)、Se‐ODPA(selenium‐octadecylphosphonic acid)或Se‐OLA(selenium‐oleylamine)等中的至少一种，但不限于此。The anion precursor of the first compound and/or the second compound includes a precursor of Se, such as a compound formed by any combination of Se and some organic substances, specifically Se-TOP (selenium-trioctylphosphine), Se-TBP (selenium-tributylphosphine), Se‐TPP (selenium‐triphenylphosphine), Se‐ODE (selenium‐1‐octadecene), Se‐OA (selenium‐oleic acid), Se‐ODA (selenium‐octadecylamine), Se‐TOA (selenium) At least one of ‐trioctylamine, Se‐ODPA (selenium‐octadecylphosphonic acid) or Se‐OLA (selenium‐oleylamine), but is not limited thereto.

所述第一种化合物和/或所述第二种化合物的阴离子前驱体包括S的前驱体，例如S与一些有机物任意组合所形成的化合物，具体可以是S‐TOP(sulfur‐trioctylphosphine，)、S‐TBP(sulfur‐tributylphosphine)、S‐TPP(sulfur‐triphenylphosphine)、S‐ODE(sulfur‐1‐octadecene)、S‐OA(sulfur‐oleic acid)、S‐ODA(sulfur‐octadecylamine)、S‐TOA(sulfur‐trioctylamine)、S‐ODPA(sulfur‐octadecylphosphonic acid)或S‐OLA(sulfur‐oleylamine)等，但不限于此；所述S的前驱体还可以烷基硫醇(alkyl thiol)，所述烷基硫醇可以是己硫醇(hexanethiol)、辛硫醇(octanethiol)、癸硫醇(decanethiol)、十二烷基硫醇(dodecanethiol)、十六烷基硫醇(hexadecanethiol)or巯丙基硅烷(mercaptopropylsilane)等中的至少一种，但不限于此。The anion precursor of the first compound and/or the second compound includes a precursor of S, for example, a compound formed by any combination of S and some organic substances, specifically, S-TOP (sulfur-trioctylphosphine), S‐TBP (sulfur-tributylphosphine), S‐TPP (sulfur‐triphenylphosphine), S‐ODE (sulfur‐1‐octadecene), S‐OA (sulfur‐oleic acid), S‐ODA (sulfur‐octadecylamine), S‐ TOA (sulfur-trioctylamine), S-ODPA (sulfur-octadecylphosphonic acid) or S-OLA (sulfur-oleylamine), etc., but is not limited thereto; the precursor of the S may also be an alkyl thiol, The alkyl mercaptan may be hexanethiol, octanethiol, decanethiol, dodecanethiol, hexadecanethiol or propyl At least one of mercaptopropylsilane and the like, but is not limited thereto.

所述第一种化合物和/或所述第二种化合物的阴离子前驱体包括Te的前驱体，所述Te的前驱体为Te‐TOP、Te‐TBP、Te‐TPP、Te‐ODE、Te‐OA、Te‐ODA、Te‐TOA、Te‐ODPA或Te‐OLA中的至少一种。The anion precursor of the first compound and/or the second compound includes a precursor of Te, and the precursor of the Te is Te‐TOP, Te‐TBP, Te‐TPP, Te‐ODE, Te‐ At least one of OA, Te‐ODA, Te‐TOA, Te‐ODPA, or Te‐OLA.

上述阳离子前躯体和阴离子前驱体可以根据最终的纳米晶体组成来确定选择其中的一种或几种：例如需要合成Cd_xZn_1‐xSe_yS_1‐y的纳米晶体时，则需要Cd的前驱体、Zn的前驱体、Se的前驱体、S的前驱体；如需要合成Cd_xZn_1‐xS的纳米晶体时，则需要Cd的前驱体、Zn的前驱体、S的前驱体；如需要合成Cd_xZn_1‐xSe的纳米晶体时，则需要Cd的前驱体、Zn的前驱体、Se的前驱体。The above cationic precursor and anionic precursor may be determined according to the final nanocrystal composition to determine one or more of them: for example, when it is required to synthesize a nanocrystal of Cd _x Zn _1‐x Se _y S _1‐y , Cd is required. Precursor, precursor of Zn, precursor of Se, precursor of S; if it is necessary to synthesize nanocrystals of Cd _x Zn _{1 -x} S, a precursor of Cd, a precursor of Zn, and a precursor of S are required; When it is necessary to synthesize a nanocrystal of Cd _x Zn _{1 -x} Se, a precursor of Cd, a precursor of Zn, and a precursor of Se are required.

在本发明的制备方法中，发生阳离子交换反应的条件优选是进行加热反应，例如加热温度在100℃至400℃之间，优选的加热温度为150℃至380℃之间。加热时间在2s至24h之间，优选的加热时间为5min至4h之间。In the production method of the present invention, the conditions under which the cation exchange reaction takes place are preferably carried out by heating, for example, a heating temperature of between 100 ° C and 400 ° C, and a preferred heating temperature of between 150 ° C and 380 ° C. The heating time is between 2 s and 24 h, and the preferred heating time is between 5 min and 4 h.

加热温度越高，阳离子交换反应的速率越快，阳离子交换的厚度范围和交换程度也越大，但厚度和程度范围会逐渐达到相对饱和的程度；类似的，加热时间越长，阳离子交换的厚度范围和交换程度也越大，但厚度和程度范围也会逐渐达到相对饱和的程度。阳离子交换的厚度范围和程度直接决定了所形成的合金组分分布。阳离子交换所形成的合金组分分布同时也由各自所形成的二元或者多元化合物纳米晶体的厚度所决定。The higher the heating temperature, the faster the rate of cation exchange reaction, the greater the thickness range and degree of exchange of cation exchange, but the thickness and extent range will gradually reach relative saturation; similarly, the longer the heating time, the thickness of cation exchange The extent and degree of exchange are also greater, but the thickness and extent range will gradually reach a relative saturation level. The thickness range and extent of cation exchange directly determines the distribution of the alloy components formed. The distribution of the alloy components formed by the cation exchange is also determined by the thickness of the binary or multicomponent compound nanocrystals formed by each.

在形成各层化合物时，阳离子前驱体与阴离子前驱体的摩尔比为100:1到1:50(具体为阳离子与阴离子的摩尔投料比)，例如在形成第一层化合物时，阳离子前驱体与阴离子前驱体的摩尔比为100:1到1:50；在形成第二层化合物时，阳离子前驱体与阴离子前驱体的摩尔比为100:1到1:50，优选的比例为20:1到1:10，优选的阳离子前驱体与阴离子前驱体的摩尔比例可保证反应速率在易于控制的范围内。In forming each layer of the compound, the molar ratio of the cationic precursor to the anionic precursor is from 100:1 to 1:50 (specifically, the molar ratio of the cation to the anion), for example, when the first layer of the compound is formed, the cationic precursor The molar ratio of the anion precursor is from 100:1 to 1:50; in forming the second layer compound, the molar ratio of the cationic precursor to the anionic precursor is from 100:1 to 1:50, and the preferred ratio is 20:1 to 1:10, the preferred molar ratio of cationic precursor to anionic precursor ensures that the reaction rate is within an easily controllable range.

通过上述制备方法所制备的纳米晶体，其发光峰波长范围为400纳米至700纳米，优选的发光峰波长范围为430纳米至660纳米，优选的量子点发光峰波长范围能够保证量子点在此范围内实现大于30％的发光量子产率。The nanocrystal prepared by the above preparation method has a luminescence peak wavelength ranging from 400 nm to 700 nm, and a preferred luminescence peak wavelength range is 430 nm to 660 nm, and a preferred quantum dot luminescence peak wavelength range can ensure quantum dots in this range. A luminescence quantum yield of greater than 30% is achieved within.

以上制备方法所制备的纳米晶体，发光量子产率范围为1％至100％，优选的发光量子产率范围为30％至100％，优选的发光量子产率范围内能够保证量子点的良好应用性。The nanocrystals prepared by the above preparation method have a luminescence quantum yield ranging from 1% to 100%, and the preferred luminescence quantum yield ranges from 30% to 100%, and the preferred luminescent quantum yield range can ensure good application of quantum dots. Sex.

本发明中，所述纳米晶体的发光峰的半高峰宽为12纳米至80纳米。 In the present invention, the half peak width of the luminescence peak of the nanocrystal is from 12 nm to 80 nm.

除了按照上述制备方法制备本发明的纳米晶体之外，本发明还提供另外一种如上所述的纳米晶体的制备方法，其包括步骤：In addition to preparing the nanocrystals of the present invention according to the above preparation method, the present invention also provides another method for preparing nanocrystals as described above, which comprises the steps of:

在径向方向上预定位置处加入一种或一种以上阳离子前驱体；同时加入一种或一种以上的阴离子前驱体，使阳离子前驱体与阴离子前驱体进行反应形成纳米晶体，并且所述纳米晶体的发光峰波长在反应过程中出现交替的蓝移和不变，从而实现在预定位置处的合金组分分布。Adding one or more cationic precursors at predetermined positions in the radial direction; simultaneously adding one or more anionic precursors, reacting the cationic precursor with the anionic precursor to form nanocrystals, and the nano The luminescence peak wavelength of the crystal appears alternately blue-shifted and unchanged during the reaction, thereby achieving distribution of the alloy composition at a predetermined position.

对于此种方法与前一种方法的不同在于，前一种是先后形成两层化合物，然后发生阳离子交换反应，从而实现本发明所需合金组分分布，而后一种方法是直接控制在预定位置处加入所需合成合金组分的阳离子前驱体和阴离子前驱体，进行反应形成纳米晶体，从而实现本发明所需合金组分分布。对于后一种方法，反应原理是反应活性高的阳离子前驱体和阴离子前驱体先发生反应，反应活性低的阳离子前驱体和阴离子前驱体后发生反应，并且在反应过程中，不同的阳离子发生阳离子交换反应，从而实现本发明所需合金组分分布。至于阳离子前驱体与阴离子前驱体的种类在前述方法中已有详述。至于反应温度、反应时间和配比等可根据具体所需合成的纳米晶体不同而有所不同，其与前述的前一种方法大体相同，后续以具体实施例进行说明。The difference between this method and the former method is that the former one forms two layers of compounds one after another, and then a cation exchange reaction occurs to achieve the distribution of the alloy components required by the present invention, and the latter method is directly controlled at a predetermined position. The cationic precursor and the anionic precursor of the desired synthetic alloy component are added to react to form nanocrystals to achieve the desired alloy component distribution of the present invention. In the latter method, the reaction principle is that the highly reactive cationic precursor and the anionic precursor react first, the reactive precursor with low reactivity and the anionic precursor react, and during the reaction, different cations undergo cations. The reaction is exchanged to achieve the desired alloy component distribution of the present invention. The types of cationic precursors and anionic precursors are detailed in the foregoing methods. The reaction temperature, the reaction time, the ratio, and the like may vary depending on the specific nanocrystals to be synthesized, and are substantially the same as the former method described above, and will be described later in the specific examples.

本发明还提供一种半导体器件，其包括如上任一项所述的纳米晶体。The present invention also provides a semiconductor device comprising the nanocrystal of any of the above.

所述半导体器件为电致发光器件、光致发光器件、太阳能电池、显示器件、光电探测器、生物探针以及非线性光学器件中的任意一种。The semiconductor device is any one of an electroluminescent device, a photoluminescence device, a solar cell, a display device, a photodetector, a bioprobe, and a nonlinear optical device.

以电致发光器件为例，以本发明所述的纳米晶体作为发光层材料的量子点电致发光器件QLED。这种量子点电致发光器件能够实现：1)高效电荷注入、2)高发光亮度、3)低驱动电压、4)高器件效率等优异器件性能。同时，本发明所述的纳米晶体，具有易于控制和多样性能级结构的特点，能够充分满足并配合器件中其他功能层的能级结构，以实现器件整体能级结构的匹配，从而有助于实现高效稳定的QLED器件。 Taking an electroluminescent device as an example, a quantum dot electroluminescent device QLED using the nanocrystal of the present invention as a light-emitting layer material. Such quantum dot electroluminescent devices are capable of achieving: 1) high efficiency charge injection, 2) high luminance, 3) low drive voltage, 4) high device efficiency and the like. At the same time, the nanocrystal of the invention has the characteristics of easy control and multi-level structure, and can fully satisfy and match the energy level structure of other functional layers in the device, so as to achieve matching of the overall energy level structure of the device, thereby contributing to Achieve efficient and stable QLED devices.

所述光致发光器件是指依赖外界光源进行照射，从而获得能量，产生激发导致发光的器件，紫外辐射、可见光及红外辐射均可引起光致发光，例如磷光与荧光。本发明的纳米晶体可作为光致发光器件的发光材料。The photoluminescent device refers to a device that relies on an external light source to obtain energy, thereby generating excitation and causing light emission, and ultraviolet radiation, visible light, and infrared radiation can cause photoluminescence, such as phosphorescence and fluorescence. The nanocrystal of the present invention can be used as a light-emitting material of a photoluminescent device.

所述太阳能电池也称光伏器件，本发明的纳米晶体可作为太阳能电池的光吸收材料，有效提高光伏器件的各项性能。The solar cell is also called a photovoltaic device, and the nanocrystal of the invention can be used as a light absorbing material of a solar cell, thereby effectively improving various performances of the photovoltaic device.

所述显示器件是指背光模组或应用所述背光模组的显示面板，所述显示面板可以应用在各种产品当中，例如显示器、平板电脑、手机、笔记本电脑、平板电视、可穿戴式显示设备或其他包含不同尺寸显示面板的产品。The display device refers to a backlight module or a display panel to which the backlight module is applied, and the display panel can be applied to various products, such as a display, a tablet, a mobile phone, a notebook computer, a flat-panel TV, and a wearable display. Equipment or other products that contain different sized display panels.

所述光电探测器是指能把光信号转换为电信号的器件，其原理是由辐射引起被照射材料电导率发生改变，将量子点材料应用在光电探测器中，具有如下优势：对垂直入射光敏感、光电导响应度高、比探测率高、探测波长连续可调及可低温制备。这种结构的光电探测器在运行过程中，量子点光敏层(即采用本发明的纳米晶体)吸收光子后产生的光生电子‐空穴对能够在内建电场的作用下发生分离，这使得该结构光电探测器具有更低的驱动电压，能在低外加偏压甚至是0外加偏压下就能工作，且易于控制。The photodetector refers to a device capable of converting an optical signal into an electrical signal. The principle is that the conductivity of the irradiated material is changed by radiation, and the quantum dot material is applied to the photodetector, which has the following advantages: normal incidence Light sensitivity, high photoconductivity, high detection rate, continuous detection wavelength and low temperature preparation. During operation of the photodetector of such a structure, the photogenerated electron-hole pairs generated by the quantum dot photosensitive layer (ie, using the nanocrystal of the present invention) can be separated by the built-in electric field, which makes the photodetector The structured photodetector has a lower drive voltage and can operate with low applied bias or even 0 applied bias and is easy to control.

所述生物探针是指对某类材料进行修饰，使其具有标记功能的器件，例如对本发明的纳米晶体进行包覆，从而形成荧光探针，应用在细胞成像或者物质检测领域中，相对于传统的有机荧光染料探针，采用本发明的纳米晶体制备的生物探针，具有荧光强度高、化学稳定性好、抗光漂白能力强的特点，具有广泛的用途。The bioprobe refers to a device that modifies a certain type of material to have a labeling function, for example, coating the nanocrystal of the present invention to form a fluorescent probe, which is used in the field of cell imaging or substance detection, as opposed to The traditional organic fluorescent dye probe adopts the biological probe prepared by the nanocrystal of the invention, and has the characteristics of high fluorescence intensity, good chemical stability and strong anti-photobleaching ability, and has wide application.

所述非线性光学器件属于光学激光技术领域，其应用较广泛，例如用于电光开光和激光调制，用于激光频率的转换、激光频率的调谐；进行光学信息处理、改善成像质量和光束质量；作为非线性标准具和双稳器件；研究物质的高激发态以及高分辨率光谱以及物质内部能量和激发的转移过程以及其他弛豫过程等。The nonlinear optical device belongs to the field of optical laser technology and is widely used, for example, for electro-optic light-on and laser modulation, for laser frequency conversion, laser frequency tuning, optical information processing, image quality improvement and beam quality; As a nonlinear etalon and bistable device; study the high-excited state of the material as well as the high-resolution spectrum and the internal energy and excitation transfer process of the material and other relaxation processes.

实施例1：基于CdZnSeS/CdZnSeS量子点的制备 Example 1: Preparation of CdZnSeS/CdZnSeS quantum dots

先将阳离子Cd的前驱体、阳离子Zn的前驱体、阴离子Se的前驱体和阴离子S的前驱体注入到反应体系中，形成Cd_yZn_1‐ySe_bS_1‐b层(其中0≤y≤1，0≤b≤1)；继续将阳离子Cd的前驱体、阳离子Zn的前驱体、阴离子Se的前驱体和阴离子S的前驱体注入到反应体系中，在上述Cd_yZn_1‐ySe_bS_1‐b层表面形成Cd_zZn_1‐zSe_cS_1‐c层(其中0≤z≤1，且z不等于y，0≤c≤1)；在一定的加热温度和加热时间等反应条件下，发生内外层纳米晶体(即上述两层化合物)中Cd与Zn离子的互换；由于阳离子的迁移距离有限且越远的迁移距离发生迁移的机率就越小，因此会在Cd_yZn_1‐ySe_bS_1‐b层与Cd_zZn_1‐zSe_cS_1‐c层的界面附近形成Cd含量和Zn含量的渐变合金组分分布，即Cd_xZn_1‐xSe_aS_1‐a，其中0≤x≤1，0≤a≤1。First, a precursor of a cationic Cd, a precursor of a cationic Zn, a precursor of an anion Se, and a precursor of an anion S are injected into a reaction system to form a Cd _y Zn _1‐y Se _b S _1‐b layer (where 0≤y) ≤1,0≤b≤1); the precursor of the cationic Cd, the precursor of the cationic Zn, the precursor of the anion Se, and the precursor of the anion S are continuously injected into the reaction system, in the above Cd _y Zn _1‐y Se _{b The} surface of the S _{1 - b} layer forms a layer of Cd _z Zn _1‐z Se _c S _1‐c (where 0≤z≤1, and z is not equal to y, 0≤c≤1); at a certain heating temperature and heating time Under the same reaction conditions, the exchange of Cd and Zn ions in the inner and outer nanocrystals (ie, the above two layers of compounds) occurs; the probability of migration due to the cation migration distance is limited and the migration distance is farther, so it will be in Cd. A gradual alloy composition distribution of Cd content and Zn content near the interface between the _y Zn _1‐y Se _b S _1‐b layer and the Cd _z Zn _1‐z Se _c S _1‐c layer, ie Cd _x Zn _1‐x Se _a S _1‐a , where 0≤x≤1, 0≤a≤1.

实施例2：基于CdZnS/CdZnS量子点的制备Example 2: Preparation based on CdZnS/CdZnS quantum dots

先将阳离子Cd的前驱体、阳离子Zn的前驱体以及阴离子S的前驱体注入到反应体系中，先形成Cd_yZn_1‐yS层(其中0≤y≤1)；继续将阳离子Cd的前驱体、阳离子Zn的前驱体以及阴离子S的前驱体注入到反应体系中，会在上述Cd_yZn_1‐yS层表面形成Cd_zZn_1‐zS层(其中0≤z≤1，且z不等于y)；在一定的加热温度和加热时间等反应条件下，发生内外层纳米晶体(即上述两层化合物)中Cd与Zn离子的互换；由于阳离子的迁移距离有限且越远的迁移距离发生迁移的机率就越小，因此会在Cd_yZn_1‐yS层与Cd_zZn_1‐zS层的界面附近形成Cd含量和Zn含量的渐变合金组分分布，即Cd_xZn_1‐xS，其中0≤x≤1。First, the precursor of the cationic Cd, the precursor of the cationic Zn, and the precursor of the anion S are injected into the reaction system to form a Cd _y Zn _{1 -y} S layer (where 0 _{≤ y ≤} ₁ ); the precursor of the cationic Cd is continued. The precursor of the bulk, cationic Zn and the precursor of the anion S are injected into the reaction system to form a Cd _z Zn _1‐z S layer on the surface of the above Cd _y Zn _1‐y S layer (where 0≤z≤1, and z Not equal to y); under certain reaction conditions such as heating temperature and heating time, the exchange of Cd and Zn ions in the inner and outer nanocrystals (ie, the above two layers of compounds) occurs; due to the limited migration distance of the cations and the further migration The smaller the probability of migration, the gradient alloy composition distribution of Cd content and Zn content near the interface between Cd _y Zn _1‐y S layer and Cd _z Zn _1‐z S layer, ie Cd _x Zn _{1 ‐x} S, where 0≤x≤1.

实施例3：基于CdZnSe/CdZnSe量子点的制备Example 3: Preparation of CdZnSe/CdZnSe quantum dots

先将阳离子Cd的前驱体、阳离子Zn的前驱体以及阴离子Se的前驱体注入到反应体系中先形成Cd_yZn_1‐ySe层(其中0≤y≤1)；继续将阳离子Cd的前驱体、阳离子Zn的前驱体以及阴离子Se的前驱体注入到反应体系中，会在上述Cd_yZn_1‐ySe层表面形成Cd_zZn_1‐zSe层(其中0≤z≤1，且z不等于y)；在一定的加热温度和加热时间等反应条件下，发生内外层纳米晶体中Cd与 Zn离子的互换；由于阳离子的迁移距离有限且越远的迁移距离发生迁移的机率就越小，因此会在Cd_yZn_1‐ySe层与Cd_zZn_1‐zSe层的界面附近形成Cd含量和Zn含量的渐变合金组分分布，即Cd_xZn_1‐xSe，其中0≤x≤1。First, the precursor of the cationic Cd, the precursor of the cationic Zn, and the precursor of the anion Se are injected into the reaction system to form a layer of Cd _y Zn _1‐y Se (where 0 _{≤ y ≤} ₁ ); the precursor of the cation Cd is continued. The precursor of the cationic Zn and the precursor of the anion Se are injected into the reaction system to form a Cd _z Zn _1‐z Se layer on the surface of the above Cd _y Zn _1‐y Se layer (where 0≤z≤1, and z does not Equivalent to y); under certain reaction conditions such as heating temperature and heating time, the exchange of Cd and Zn ions in the inner and outer nanocrystals occurs; the probability of migration due to the limited migration distance of the cation and the farther migration distance is smaller. Therefore, a graded alloy composition distribution of Cd content and Zn content is formed near the interface between the Cd _y Zn _1‐y Se layer and the Cd _z Zn _1‐z Se layer, that is, Cd _x Zn _1‐x Se, where 0≤x ≤1.

实施例4：基于CdS/ZnS量子点的制备Example 4: Preparation based on CdS/ZnS quantum dots

先将阳离子Cd的前驱体和阴离子S的前驱体注入到反应体系中，先形成CdS层；继续将阳离子Zn的前驱体和阴离子S的前驱体注入到反应体系中，会在上述CdS层表面形成ZnS层；在一定的加热温度和加热时间等反应条件下，外层的Zn阳离子会逐渐向内层迁移，并与Cd阳离子发生阳离子交换反应，即Cd离子向外层迁移，发生了Cd与Zn离子的互换；由于阳离子的迁移距离有限且越远的迁移距离发生迁移的机率就越小，因此会在CdS层与ZnS层的界面附近形成Cd含量沿着径向向外逐渐减少、Zn含量沿着径向向外逐渐增加的渐变合金组分分布，即Cd_xZn_1‐xS，其中0≤x≤1且x自内向外(径向方向)从1单调递减为0。First, the precursor of the cationic Cd and the precursor of the anion S are injected into the reaction system to form a CdS layer; the precursor of the cationic Zn and the precursor of the anion S are continuously injected into the reaction system to form on the surface of the CdS layer. ZnS layer; under certain reaction conditions such as heating temperature and heating time, the Zn cation of the outer layer will gradually migrate to the inner layer and undergo cation exchange reaction with Cd cation, that is, Cd ion migrates to the outer layer, and Cd and Zn occur. Ion exchange; the migration distance of the cation is limited and the migration distance of the migration distance is smaller, so the Cd content is gradually decreased along the radial direction and the Zn content is formed near the interface between the CdS layer and the ZnS layer. A graded alloy composition distribution that gradually increases outward in the radial direction, that is, Cd _x Zn _{1 - x} S, where 0 ≤ x ≤ 1 and x decreases monotonically from 1 to 0 from the inside to the outside (radial direction).

实施例5：基于CdSe/ZnSe量子点的制备Example 5: Preparation based on CdSe/ZnSe quantum dots

先将阳离子Cd的前驱体和阴离子Se的前驱体注入到反应体系中先形成CdSe层；继续将阳离子Zn的前驱体和阴离子Se的前驱体注入到反应体系中，会在上述CdSe层表面形成ZnSe层；在一定的加热温度和加热时间等反应条件下，外层的Zn阳离子会逐渐向内层迁移，并与Cd阳离子发生阳离子交换反应，即Cd离子向外层迁移，发生了Cd与Zn离子的互换；由于阳离子的迁移距离有限且越远的迁移距离发生迁移的机率就越小，因此会在CdSe层与ZnSe层的界面附近形成Cd含量沿着径向向外逐渐减少、Zn含量沿着径向向外逐渐增加的渐变合金组分分布，即Cd_xZn_1‐xSe，其中0≤x≤1且x自内向外(径向方向)从1单调递减为0。The precursor of the cationic Cd and the precursor of the anion Se are first injected into the reaction system to form a CdSe layer; the precursor of the cationic Zn and the precursor of the anion Se are continuously injected into the reaction system to form ZnSe on the surface of the CdSe layer. Under certain reaction conditions such as heating temperature and heating time, the Zn cation of the outer layer gradually migrates to the inner layer and undergoes cation exchange reaction with Cd cations, that is, Cd ions migrate to the outer layer, and Cd and Zn ions occur. The interchangeability of the cations due to the limited migration distance of the cations and the migration distance of the migration distance is smaller. Therefore, the Cd content near the interface between the CdSe layer and the ZnSe layer is gradually decreased along the radial direction, and the Zn content is gradually decreased. The distribution of the graded alloy composition gradually increasing radially outward, that is, Cd _x Zn _{1 - x} Se, where 0 ≤ x ≤ 1 and x is monotonously decreasing from 1 to 0 from the inside to the outside (radial direction).

实施例6：基于CdSeS/ZnSeS量子点的制备Example 6: Preparation based on CdSeS/ZnSeS quantum dots

先将阳离子Cd的前驱体、阴离子Se的前驱体以及阴离子S的前驱体注入到反应体系中先形成CdSe_bS_1‐b层(其中0≤b≤1)；继续将阳离子Zn 的前驱体、阴离子Se的前驱体以及阴离子S的前驱体注入到反应体系中，会在上述CdSe_bS_1‐b层表面形成ZnSe_cS_1‐c层(其中0≤c≤1)；在一定的加热温度和加热时间等反应条件下，外层的Zn阳离子会逐渐向内层迁移，并与Cd阳离子发生阳离子交换反应，即Cd离子向外层迁移，发生了Cd与Zn离子的互换；由于阳离子的迁移距离有限且越远的迁移距离发生迁移的机率就越小，因此会在CdSe_bS_1‐b层与ZnSe_cS_1‐c层的界面附近形成Cd含量沿着径向向外逐渐减少、Zn含量沿着径向向外逐渐增加的渐变合金组分分布，即Cd_xZn_1‐xSe_aS_1‐a，其中0≤x≤1且x自内向外(径向方向)从1单调递减为0，0≤a≤1。First, a precursor of the cationic Cd, a precursor of the anion Se, and a precursor of the anion S are injected into the reaction system to form a CdSe _b S _{1 -b} layer (where 0 ≤ b ≤ 1); the precursor of the cationic Zn is continued, The precursor of the anion Se and the precursor of the anion S are injected into the reaction system to form a layer of ZnSe _c S _{1 -c on the} surface of the above CdSe _b S _{1 -b} layer (where 0 ≤ _c ≤ 1); at a certain heating temperature Under the reaction conditions such as heating time, the Zn cation of the outer layer gradually migrates to the inner layer and undergoes cation exchange reaction with the Cd cation, that is, the Cd ion migrates to the outer layer, and the exchange of Cd and Zn ions occurs; The migration distance is limited and the migration distance of the migration distance is smaller. Therefore, the Cd content in the vicinity of the interface between the CdSe _b S _1‐b layer and the ZnSe _c S _1‐c layer gradually decreases along the radial direction. The distribution of the grading alloy composition with increasing Zn content along the radial direction, ie Cd _x Zn _1‐x Se _a S _1‐a , where 0≤x≤1 and x monotonous from the inside to the outside (radial direction) from 1 Decrement to 0, 0 ≤ a ≤ 1.

实施例7：基于ZnS/CdS量子点的制备Example 7: Preparation based on ZnS/CdS quantum dots

先将阳离子Zn的前驱体和阴离子S的前驱体注入到反应体系中先形成ZnS层；继续将阳离子Cd的前驱体和阴离子S的前驱体注入到反应体系中，会在上述ZnS层表面形成CdS层；在一定的加热温度和加热时间等反应条件下，外层的Cd阳离子会逐渐向内层迁移，并与Zn阳离子发生阳离子交换反应，即Zn离子向外层迁移，发生了Cd与Zn离子的互换；由于阳离子的迁移距离有限且越远的迁移距离发生迁移的机率就越小，因此会在ZnS层与CdS层的界面附近形成Zn含量沿着径向向外逐渐减少、Cd含量沿着径向向外逐渐增加的渐变合金组分分布，即Cd_xZn_1‐xS，其中0≤x≤1且x自内向外(径向方向)从0单调递增为1。The precursor of the cationic Zn and the precursor of the anion S are first injected into the reaction system to form a ZnS layer; the precursor of the cationic Cd and the precursor of the anion S are continuously injected into the reaction system to form a CdS on the surface of the ZnS layer. Under certain reaction conditions such as heating temperature and heating time, the Cd cation of the outer layer gradually migrates to the inner layer and undergoes cation exchange reaction with the Zn cation, that is, Zn ions migrate to the outer layer, and Cd and Zn ions occur. The interchangeability of the cations due to the limited migration distance of the cations and the migration distance of the longer distances, so that the Zn content in the vicinity of the interface between the ZnS layer and the CdS layer gradually decreases along the radial direction, and the Cd content decreases. The distribution of the graded alloy composition gradually increasing radially outward, that is, Cd _x Zn _{1 - x} S, where 0 ≤ x ≤ 1 and x monotonously increases from 0 to 1 from the inside to the outside (radial direction).

实施例8：基于ZnSe/CdSe量子点的制备Example 8: Preparation based on ZnSe/CdSe quantum dots

先将阳离子Zn的前驱体和阴离子Se的前驱体注入到反应体系中先形成ZnSe层；继续将阳离子Cd的前驱体和阴离子Se的前驱体注入到反应体系中，会在上述ZnSe层表面形成CdSe层；在一定的加热温度和加热时间等反应条件下，外层的Cd阳离子会逐渐向内层迁移，并与Zn阳离子发生阳离子交换反应，即Zn离子向外层迁移，发生了Cd与Zn离子的互换；由于阳离子的迁移距离有限且越远的迁移距离发生迁移的机率就越小，因此会在ZnSe层与CdSe层的界面附近形成Zn含量沿着径向向外逐渐减少、Cd含量沿着径向向外逐渐增加的渐变合金组分分布，即Cd_xZn_1‐xSe，其中0≤x≤1且x自内向外(径向方向)从0单调递增为1。First, a precursor of a cationic Zn and a precursor of an anion Se are injected into the reaction system to form a ZnSe layer; and a precursor of a cationic Cd and a precursor of an anion Se are continuously injected into the reaction system to form a CdSe on the surface of the ZnSe layer. Under certain reaction conditions such as heating temperature and heating time, the Cd cation of the outer layer gradually migrates to the inner layer and undergoes cation exchange reaction with the Zn cation, that is, Zn ions migrate to the outer layer, and Cd and Zn ions occur. The interchangeability of the cations due to the limited migration distance of the cations and the migration distance of the migration distance is smaller. Therefore, the Zn content near the interface between the ZnSe layer and the CdSe layer gradually decreases along the radial direction, and the Cd content decreases. The distribution of the graded alloy composition gradually increasing radially outward, that is, Cd _x Zn _{1 - x} Se, where 0 ≤ x ≤ 1 and x monotonically increases from 0 to 1 from the inside to the outside (radial direction).

实施例9：基于ZnSeS/CdSeS量子点的制备Example 9: Preparation based on ZnSeS/CdSeS quantum dots

先将阳离子Zn的前驱体、阴离子Se的前驱体以及阴离子S的前驱体注入到反应体系中先形成ZnSe_bS_1‐b层(其中0≤b≤1)；继续将阳离子Cd的前驱体、阴离子Se的前驱体以及阴离子S的前驱体注入到反应体系中，会在上述ZnSebS1‐b层表面形成CdSe_cS_1‐c层(其中0≤c≤1)；在一定的加热温度和加热时间等反应条件下，外层的Cd阳离子会逐渐向内层迁移，并与Zn阳离子发生阳离子交换反应，即Zn离子向外层迁移，发生了Cd与Zn离子的互换；由于阳离子的迁移距离有限且越远的迁移距离发生迁移的机率就越小，因此会在ZnSe_bS_1‐b层与CdSe_cS_1‐c层的界面附近形成Zn含量沿着径向向外逐渐减少、Cd含量沿着径向向外逐渐增加的渐变合金组分分布，即Cd_xZn_1‐xSe_aS_1‐a，其中0≤x≤1且x自内向外从0单调递增为1，0≤a≤1。First, a precursor of a cationic Zn, a precursor of an anion Se, and a precursor of an anion S are first injected into a reaction system to form a ZnSe _b S _{1 -b} layer (where 0 ≤ b ≤ 1); the precursor of the cationic Cd is continued, The precursor of the anion Se and the precursor of the anion S are injected into the reaction system to form a layer of CdSe _c S _{1-c on the} surface of the above ZnSebS1‐b layer (where 0≤c≤1); at a certain heating temperature and heating time Under the same reaction conditions, the Cd cation of the outer layer will gradually migrate to the inner layer and undergo cation exchange reaction with the Zn cation, that is, the Zn ion migrates to the outer layer, and the exchange of Cd and Zn ions occurs; the migration distance of the cation is limited. The farther the migration distance is less likely to migrate, the Zn content in the vicinity of the interface between the ZnSe _b S _1‐b layer and the CdSe _c S _1‐c layer will gradually decrease along the radial direction, and the Cd content will decrease. The distribution of the graded alloy composition gradually increasing radially outward, namely Cd _x Zn _1‐x Se _a S _1‐a , where 0≤x≤1 and x monotonically increasing from 0 to 1,0≤a≤ from the inside to the outside 1.

实施例10：具有量子阱能级结构的蓝色量子点的制备Example 10: Preparation of Blue Quantum Dots with Quantum Well Level Structure

油酸镉和油酸锌前驱体制备：将1mmol氧化镉(CdO)，9mmol乙酸锌[Zn(acet)₂]，8mL油酸(Oleic acid)和15mL十八烯(1‐Octadecene)置于100mL三口烧瓶中，于80℃下进行真空脱气60min。然后将其切换成氮气气氛下，并于该温度下保存以备待用。Preparation of cadmium oleate and zinc oleate precursor: 1 mmol of cadmium oxide (CdO), 9 mmol of zinc acetate [Zn(acet) ₂ ], 8 mL of oleic acid (Oleic acid) and 15 mL of octadecene (1 -Octadecene) were placed in 100 mL In a three-necked flask, vacuum degassing was carried out at 80 ° C for 60 min. It is then switched to a nitrogen atmosphere and stored at this temperature for use.

将2mmol硫粉(Sulfur powder)溶解在3mL的十八烯(1‐Octadecene)中，得到硫十八烯前驱体。2 mmol of sulfur powder (Sulfur powder) was dissolved in 3 mL of octadecene (1 - Octadecene) to obtain a thiooctadecene precursor.

将6mmol硫粉(Sulfur powder)溶解在3mL的三辛基膦(Trioctylphosphine)中，得到硫化三辛基膦前驱体。6 mmol of sulfur powder (Sulfur powder) was dissolved in 3 mL of Trioctylphosphine to obtain a trioctylphosphine sulfide precursor.

将0.6mmol氧化镉(CdO)，0.6mL油酸(Oleic acid)和5.4mL十八烯(1‐Octadecene)置于100mL三口烧瓶中，在氮气氛围下250℃加热回流120min，得到透明的油酸镉前驱体。 0.6 mmol of cadmium oxide (CdO), 0.6 mL of oleic acid (Oleic acid) and 5.4 mL of octadecene (1 -Octadecene) were placed in a 100 mL three-necked flask, and heated under reflux in a nitrogen atmosphere at 250 ° C for 120 min to obtain a transparent oleic acid. Cadmium precursor.

在氮气氛围下，将油酸镉和油酸锌前驱体升温至310℃，将硫十八烯前驱体快速注入到反应体系中，先生成Cd_xZn_1‐xS，反应10min后，将反应体系温度降至280℃，接着将2mL的硫化三辛基膦前驱体和6mL油酸镉前驱体分别以3mL/h和10mL/h的速率同时注入到反应体系中。注入40min后，将反应体系温度升温至310℃，将1mL硫化三辛基膦前驱体以3mL/h的速率注入到反应体系中，反应结束后，待反应液冷却至室温后，用甲苯和无水甲醇将产物反复溶解、沉淀，离心提纯，得到量子阱能级结构的蓝色量子点。The cadmium oleate and zinc oleate precursors were heated to 310 ° C under a nitrogen atmosphere, and the thiooctadecene precursor was rapidly injected into the reaction system to form Cd _x Zn _{1 -x} S. After 10 minutes of reaction, the reaction was carried out. The temperature of the system was lowered to 280 ° C, and then 2 mL of a trioctylphosphine sulfide precursor and 6 mL of a cadmium oleate precursor were simultaneously injected into the reaction system at a rate of 3 mL/h and 10 mL/h, respectively. After 40 min of injection, the temperature of the reaction system was raised to 310 ° C, and 1 mL of the trioctylphosphine sulfide precursor was injected into the reaction system at a rate of 3 mL/h. After the reaction was completed, the reaction solution was cooled to room temperature, and then toluene and no. The product was repeatedly dissolved and precipitated by water methanol, and purified by centrifugation to obtain a blue quantum dot of a quantum well level structure.

实施例11：具有量子阱能级结构的绿色量子点的制备Example 11: Preparation of green quantum dots with quantum well level structure

油酸镉和油酸锌前驱体制备：将0.4mmol氧化镉(CdO)，8mmol乙酸锌[Zn(acet)₂]，10mL油酸(Oleic acid)和20mL十八烯(1‐Octadecene)置于100mL三口烧瓶中，于80℃下进行真空脱气60min。然后将其切换成氮气气氛下，并于该温度下保存以备待用。Preparation of cadmium oleate and zinc oleate precursor: 0.4 mmol of cadmium oxide (CdO), 8 mmol of zinc acetate [Zn(acet) ₂ ], 10 mL of oleic acid (Oleic acid) and 20 mL of octadecene (1 -Octadecene) were placed. In a 100 mL three-necked flask, vacuum degassing was carried out at 80 ° C for 60 min. It is then switched to a nitrogen atmosphere and stored at this temperature for use.

将2mmol硒粉(Selenium powder)，4mmol硫粉(Sulfur powder)溶解在4mL的三辛基膦(Trioctylphosphine)中，得到硒化三辛基膦‐硫化三辛基膦前驱体。2 mmol of Selenium powder and 4 mmol of sulfur powder were dissolved in 4 mL of Trioctylphosphine to obtain a trioctylphosphine selenide-trioctylphosphine sulfide precursor.

将2mmol硫粉(Sulfur powder)溶解在2mL的三辛基膦(Trioctylphosphine)中，得到硫化三辛基膦前驱体。2 mmol of sulfur powder (Sulfur powder) was dissolved in 2 mL of Trioctylphosphine to obtain a trioctylphosphine sulfide precursor.

将0.6mmol氧化镉(CdO)，0.6mL油酸(Oleic acid)和5.4mL十八烯(1‐Octadecene)置于100mL三口烧瓶中，在氮气氛围下250℃加热回流120min，得到透明的油酸镉前驱体。0.6 mmol of cadmium oxide (CdO), 0.6 mL of oleic acid (Oleic acid) and 5.4 mL of octadecene (1 -Octadecene) were placed in a 100 mL three-necked flask, and heated under reflux in a nitrogen atmosphere at 250 ° C for 120 min to obtain a transparent oleic acid. Cadmium precursor.

在氮气氛围下，将油酸镉和油酸锌前驱体升温至310℃，将硒化三辛基膦‐硫化三辛基膦前驱体快速注入到反应体系中，先生成Cd_xZn_1‐xSe_yS_1‐y，反应10min后，将反应体系温度降至280℃，接着将1.2mL的硫化三辛基膦前驱体和6mL油酸镉前驱体分别以2mL/h和10mL/h的速率注入到反应体系中，直至前驱体注入完。将反应体系温度升温至310℃，将0.8mL硫化三辛基膦前驱体以2mL/h的速率注入到反应体系中。反应结束后，待反应液冷却至室温后，用甲苯和无水甲醇将产物反复溶解、沉淀，离心提纯，得到具有量子阱能级结构的绿色量子点。The cadmium oleate and zinc oleate precursors were heated to 310 ° C under a nitrogen atmosphere, and the trioctylphosphine trisulfide sulfide trioctylphosphine precursor was rapidly injected into the reaction system to form Cd _x Zn _1‐x. Se _y S _1‐y , after reacting for 10 min, the temperature of the reaction system was lowered to 280 ° C, and then 1.2 mL of the trioctylphosphine sulfide precursor and 6 mL of the cadmium oleate precursor were respectively at a rate of 2 mL/h and 10 mL/h. Inject into the reaction system until the precursor is injected. The temperature of the reaction system was raised to 310 ° C, and 0.8 mL of a trioctylphosphine sulfide precursor was injected into the reaction system at a rate of 2 mL / h. After completion of the reaction, after the reaction solution was cooled to room temperature, the product was repeatedly dissolved and precipitated with toluene and anhydrous methanol, and purified by centrifugation to obtain a green quantum dot having a quantum well level structure.

实施例12：具有量子阱能级结构的红色量子点的制备Example 12: Preparation of red quantum dots with quantum well level structure

油酸镉和油酸锌前驱体制备：将0.8mmol氧化镉(CdO)，12mmol乙酸锌[Zn(acet)₂]，14mL油酸(Oleic acid)和20mL十八烯(1‐Octadecene)置于100mL三口烧瓶中，于80℃下进行真空脱气60min。然后将其切换成氮气气氛下，并于该温度下保存以备待用。Preparation of cadmium oleate and zinc oleate precursor: 0.8 mmol of cadmium oxide (CdO), 12 mmol of zinc acetate [Zn(acet) ₂ ], 14 mL of oleic acid (Oleic acid) and 20 mL of octadecene (1 -Octadecene) were placed. In a 100 mL three-necked flask, vacuum degassing was carried out at 80 ° C for 60 min. It is then switched to a nitrogen atmosphere and stored at this temperature for use.

将2mmol硒粉(Selenium powder)在4mL的三辛基膦(Trioctylphosphine)中，得到硒化三辛基膦前驱体。2 mmol of Selenium powder was placed in 4 mL of Trioctylphosphine to obtain a trioctylphosphine selenide precursor.

将0.2mmol硒粉(Selenium powder)，0.6mmol硫粉(Sulfur powder)溶解在2mL的三辛基膦(Trioctylphosphine)中，得到硒化三辛基膦‐硫化三辛基膦前驱体。0.2 mmol of Selenium powder and 0.6 mmol of sulfur powder (Sulfur powder) were dissolved in 2 mL of Trioctylphosphine to obtain a trioctylphosphine selenide-trioctylphosphine sulfide precursor.

将0.3mmol氧化镉(CdO)，0.3mL油酸(Oleic acid)和2.7mL十八烯(1‐Octadecene)置于50mL三口烧瓶中，在氮气氛围下250℃加热回流120min，得到透明的油酸镉前驱体。0.3 mmol of cadmium oxide (CdO), 0.3 mL of oleic acid (Oleic acid) and 2.7 mL of octadecene (1 -Octadecene) were placed in a 50 mL three-necked flask, and heated under reflux in a nitrogen atmosphere at 250 ° C for 120 min to obtain a transparent oleic acid. Cadmium precursor.

在氮气氛围下，将油酸镉和油酸锌前驱体升温至310℃，将硒化三辛基膦前驱体快速注入到反应体系中，先生成Cd_xZn_1‐xSe，反应10min后，将反应体系温度降至280℃，接着将1mL硒化三辛基膦‐硫化三辛基膦前驱体和3mL油酸镉前驱体分别以2mL/h和6mL/h的速率注入到反应体系中。将反应体系温度升温至310℃，将1mL硒化三辛基膦‐硫化三辛基膦前驱体以4mL/h的速率注入到反应体系中。反应结束后，待反应液冷却至室温后，用甲苯和无水甲醇将产物反复溶解、沉淀，离心提纯，得到具有量子阱能级结构的红色量子点。The cadmium oleate and zinc oleate precursors were heated to 310 ° C under a nitrogen atmosphere, and the trioctylphosphine precursor was quickly injected into the reaction system to form Cd _x Zn _{1 -x} Se. After 10 minutes of reaction, The temperature of the reaction system was lowered to 280 ° C, and then 1 mL of a trioctylphosphine sulfide-trioctylphosphine sulfide precursor and 3 mL of a cadmium oleate precursor were injected into the reaction system at a rate of 2 mL/h and 6 mL/h, respectively. The temperature of the reaction system was raised to 310 ° C, and 1 mL of a trioctylphosphine selenide-trioctylphosphine sulfide precursor was injected into the reaction system at a rate of 4 mL/h. After completion of the reaction, after the reaction solution was cooled to room temperature, the product was repeatedly dissolved and precipitated with toluene and anhydrous methanol, and purified by centrifugation to obtain a red quantum dot having a quantum well level structure.

实施例13Example 13

本实施例量子点发光二极管，如图2所示，自下而上依次包括：ITO衬底11、底电极12、PEDOT：PSS空穴注入层13、poly‐TPD空穴传输层14、量子点发光层15、ZnO电子传输层16及Al顶电极17。The quantum dot light emitting diode of this embodiment, as shown in FIG. 2, includes: ITO lining from bottom to top. Bottom 11, bottom electrode 12, PEDOT: PSS hole injection layer 13, poly-TPD hole transport layer 14, quantum dot light-emitting layer 15, ZnO electron transport layer 16, and Al top electrode 17.

上述量子点发光二极管的制备步骤如下：The preparation steps of the above quantum dot light emitting diode are as follows:

在ITO衬底11上依次制备底电极12、30nm PEDOT：PSS空穴注入层13和30nm poly‐TPD空穴传输层14后，在poly‐TPD空穴传输层14上制备一层量子点发光层15，厚度为20nm，随后再在量子点发光层15上制备40nm ZnO电子传输层16及100nm Al顶电极17。所述量子点发光层15的纳米晶体为如实施例10所述的纳米晶体。After sequentially preparing the bottom electrode 12, the 30 nm PEDOT:PSS hole injection layer 13 and the 30 nm poly-TPD hole transport layer 14 on the ITO substrate 11, a quantum dot light-emitting layer is prepared on the poly-TPD hole transport layer 14. 15. The thickness was 20 nm, and then a 40 nm ZnO electron transport layer 16 and a 100 nm Al top electrode 17 were prepared on the quantum dot light-emitting layer 15. The nanocrystal of the quantum dot luminescent layer 15 is a nanocrystal as described in Example 10.

实施例14Example 14

本实施例中量子点发光二极管，如图3所示，自下而上依次包括：ITO衬底21、底电极22、PEDOT：PSS空穴注入层23、Poly(9‐vinylcarbazole)(PVK)空穴传输层24、量子点发光层25、ZnO电子传输层26及Al顶电极27。The quantum dot light emitting diode in this embodiment, as shown in FIG. 3, includes, in order from bottom to top, an ITO substrate 21, a bottom electrode 22, a PEDOT: PSS hole injection layer 23, and a poly(9-vinylcarbazole) (PVK) space. The hole transport layer 24, the quantum dot light-emitting layer 25, the ZnO electron transport layer 26, and the Al top electrode 27.

在ITO衬底21上依次制备底电极22、30nm PEDOT：PSS空穴注入层23和30nm PVK空穴传输层24后，在PVK空穴传输层24上制备一层量子点发光层25，厚度为20nm，随后再在量子点发光层25上制备40nm ZnO电子传输层26及100nm Al顶电极27。所述量子点发光层25的纳米晶体为如实施例11所述的纳米晶体。After sequentially preparing the bottom electrode 22, the 30 nm PEDOT:PSS hole injection layer 23 and the 30 nm PVK hole transport layer 24 on the ITO substrate 21, a quantum dot light-emitting layer 25 is prepared on the PVK hole transport layer 24, and the thickness is At 20 nm, a 40 nm ZnO electron transport layer 26 and a 100 nm Al top electrode 27 were subsequently prepared on the quantum dot light-emitting layer 25. The nanocrystal of the quantum dot luminescent layer 25 is a nanocrystal as described in Example 11.

实施例15Example 15

本实施例量子点发光二极管，如图4所示，自下而上依次包括：ITO衬底31、底电极32、PEDOT：PSS空穴注入层33、poly‐TPD空穴传输层34、量子点发光层35、TPBi电子传输层36及Al顶电极37。The quantum dot light emitting diode of this embodiment, as shown in FIG. 4, includes, in order from bottom to top, an ITO substrate 31, a bottom electrode 32, a PEDOT: PSS hole injection layer 33, a poly-TPD hole transport layer 34, and a quantum dot. The light-emitting layer 35, the TPBi electron transport layer 36, and the Al top electrode 37.

在ITO衬底31上依次制备底电极32、30nm PEDOT：PSS空穴注入层33和30nm poly‐TPD空穴传输层34后，在poly‐TPD空穴传输层34上制备一层量子点发光层35，厚度为20nm，随后再在量子点发光层35上通过真空蒸镀方法制备30nm TPBi电子传输层36及100nm Al顶电极37。所述量子点发光层35的纳米晶体为如实施例12所述的纳米晶体。After sequentially preparing the bottom electrode 32, the 30 nm PEDOT:PSS hole injection layer 33 and the 30 nm poly-TPD hole transport layer 34 on the ITO substrate 31, a quantum dot light-emitting layer is prepared on the poly-TPD hole transport layer 34. 35, the thickness is 20 nm, and then pass through the quantum dot light-emitting layer 35 The 30 nm TPBi electron transport layer 36 and the 100 nm Al top electrode 37 were prepared by an air evaporation method. The nanocrystal of the quantum dot luminescent layer 35 is a nanocrystal as described in Example 12.

实施例16Example 16

本实施例量子点发光二极管，如图5所示，自下而上依次包括：ITO衬底41、底电极42、ZnO电子传输层43、量子点发光层44、NPB空穴传输层45、MoO₃空穴注入层46及Al顶电极47。The quantum dot light-emitting diode of this embodiment, as shown in FIG. 5, comprises, in order from bottom to top, an ITO substrate 41, a bottom electrode 42, a ZnO electron transport layer 43, a quantum dot light-emitting layer 44, an NPB hole transport layer 45, and a MoO. ₃ hole injection layer 46 and Al top electrode 47.

在ITO衬底41上依次制备底电极42，40nm ZnO电子传输层43，在ZnO电子传输层43上制备一层量子点发光层44，厚度为20nm,随后再通过真空蒸镀方法制备30nm NPB空穴传输层45，5nm MoO₃空穴注入层46及100nm Al顶电极47。所述量子点发光层44的纳米晶体为如实施例10所述的纳米晶体。A bottom electrode 42 and a 40 nm ZnO electron transport layer 43 are sequentially prepared on the ITO substrate 41, and a quantum dot light-emitting layer 44 is formed on the ZnO electron transport layer 43 to a thickness of 20 nm, and then a 30 nm NPB space is prepared by a vacuum evaporation method. The hole transport layer 45, the ₅ nm MoO ₃ hole injection layer 46 and the 100 nm Al top electrode 47. The nanocrystal of the quantum dot luminescent layer 44 is a nanocrystal as described in Example 10.

实施例17Example 17

本实施例量子点发光二极管，如图6所示，自下而上依次包括：玻璃衬底51、Al电极52，PEDOT：PSS空穴注入层53、poly‐TPD空穴传输层54、量子点发光层55、ZnO电子传输层56及ITO顶电极57。The quantum dot light emitting diode of this embodiment, as shown in FIG. 6, includes, in order from bottom to top, a glass substrate 51, an Al electrode 52, a PEDOT: PSS hole injection layer 53, a poly-TPD hole transport layer 54, and a quantum dot. The light-emitting layer 55, the ZnO electron transport layer 56, and the ITO top electrode 57.

在玻璃衬底51上通过真空蒸镀方法制备100nm Al电极52，然后依次制备30nm PEDOT：PSS空穴注入层53和30nm poly‐TPD空穴传输层54后，在poly‐TPD空穴传输层54上制备一层量子点发光层55，厚度为20nm，随后再在量子点发光层55上制备40nm ZnO电子传输层56，最后通过溅射方法制备120nm ITO作为顶电极57。所述量子点发光层55的纳米晶体为如实施例11所述的纳米晶体。A 100 nm Al electrode 52 was prepared on the glass substrate 51 by a vacuum evaporation method, and then a 30 nm PEDOT:PSS hole injection layer 53 and a 30 nm poly-TPD hole transport layer 54 were sequentially prepared, followed by a poly-TPD hole transport layer 54. A quantum dot light-emitting layer 55 was prepared to have a thickness of 20 nm, and then a 40 nm ZnO electron transport layer 56 was prepared on the quantum dot light-emitting layer 55. Finally, 120 nm of ITO was prepared as a top electrode 57 by a sputtering method. The nanocrystal of the quantum dot luminescent layer 55 is a nanocrystal as described in Example 11.

实施例18Example 18

本实施例量子点发光二极管，如图7所示，自下而上依次包括：玻璃衬底61、Al电极62，ZnO电子传输层63，量子点发光层64，NPB空穴传输层65，MoO₃空穴注入层66及ITO顶电极67。The quantum dot light-emitting diode of this embodiment, as shown in FIG. 7, includes, in order from bottom to top, a glass substrate 61, an Al electrode 62, a ZnO electron transport layer 63, a quantum dot light-emitting layer 64, an NPB hole transport layer 65, and a MoO. ₃ hole injection layer 66 and ITO top electrode 67.

在玻璃衬底61上通过真空蒸镀方法制备100nm Al电极62，然后依次制备40nm ZnO电子传输层63，20nm量子点发光层64，随后再通过真空蒸镀方法制备30nm NPB空穴传输层65，5nm MoO₃空穴注入层66，最后通过溅射方法制备120nm ITO作为顶电极67。所述量子点发光层的纳米晶体为如实施例12所述的纳米晶体。A 100 nm Al electrode 62 is prepared on the glass substrate 61 by a vacuum evaporation method, and then a 40 nm ZnO electron transport layer 63, a 20 nm quantum dot light emitting layer 64 is sequentially prepared, and then a 30 nm NPB hole transport layer 65 is prepared by a vacuum evaporation method. 5 nm MoO ₃ hole injection layer 66, and finally 120 nm ITO was prepared as a top electrode 67 by a sputtering method. The nanocrystal of the quantum dot luminescent layer is a nanocrystal as described in Example 12.

应当理解的是，本发明的应用不限于上述的举例，对本领域普通技术人员来说，可以根据上述说明加以改进或变换，所有这些改进和变换都应属于本发明所附权利要求的保护范围。 It is to be understood that the application of the present invention is not limited to the above-described examples, and those skilled in the art can make modifications and changes in accordance with the above description, all of which are within the scope of the appended claims.

Claims

一种纳米晶体，其特征在于，所述纳米晶体包含S个位于纳米晶体中心的中心结构单元和N个位于纳米晶体中心外并依次排布的环绕结构单元，其中N≥2，S≥1，所述中心结构单元与环绕结构单元均为量子点结构单元；A nanocrystal, characterized in that the nanocrystal comprises S central structural units located at the center of the nanocrystal and N surrounding structural units located outside the center of the nanocrystal and arranged in sequence, wherein N≥2, S≥1, The central structural unit and the surrounding structural unit are both quantum dot structural units;

所述中心结构单元为径向方向上越向外能级宽度越宽的渐变合金组分结构；The central structural unit is a graded alloy composition structure in which the width of the outer level is wider in the radial direction;

所述N个环绕结构单元由M个第一环绕结构单元以及(N‐M)个第二环绕结构单元组成，所述M个第一环绕结构单元为径向方向上能级宽度一致的均一组分结构，所述(N‐M)个第二环绕结构单元为径向方向上越向外能级宽度越宽的渐变合金组分结构，M≥1；The N surrounding structural units are composed of M first surrounding structural units and (N-M) second surrounding structural units, the M first surrounding structural units being a uniform set of energy levels in the radial direction. a sub-structure, the (N-M) second surrounding structural unit is a graded alloy composition structure having a wider outer-level width in a radial direction, M≥1;

至少有一个第一环绕结构单元位于第二环绕结构单元与中心结构单元之间，相邻的中心结构单元的能级是连续的，相邻的第二环绕结构单元的能级也是连续的。At least one first surrounding structural unit is located between the second surrounding structural unit and the central structural unit, the energy levels of the adjacent central structural units are continuous, and the energy levels of the adjacent second surrounding structural units are also continuous.
根据权利要求1所述的纳米晶体，其特征在于，所述中心结构单元为包含II族和VI族元素的渐变合金组分结构；所述第一环绕结构单元为包含II族和VI族元素的均一合金组分结构；且所述第二环绕结构单元为包含II族和VI族元素的渐变合金组分结构。The nanocrystal according to claim 1, wherein the central structural unit is a graded alloy component structure comprising Group II and Group VI elements; and the first surrounding structural unit is a Group II and Group VI element. a uniform alloy component structure; and the second surrounding structural unit is a graded alloy component structure comprising Group II and Group VI elements.
根据权利要求2所述的纳米晶体，其特征在于，所述中心结构单元的合金组分为Cd_x0Zn_1‐x0Se_y0S_1‐y0，其中0≤x0≤1，0≤y0≤1，并且x0和y0不同时为0和不同时为1。The nanocrystal according to claim 2, wherein the alloy component of the central structural unit is Cd _x0 Zn _{1 - x0} Se _y0 S _{1 - y0} , where ₀ ≤ _x0 ≤ _{1, 0} ≤ _y0 ≤ 1, And x0 and y0 are not 0 at the same time and 1 at the same time.
根据权利要求2所述的纳米晶体，其特征在于，所述第一环绕结构单元的合金组分为Cd_x1Zn_1‐x1Se_y1S_1‐y1，其中0≤x1≤1，0≤y1≤1，并且x1和y1不同时为0和不同时为1，且x1和y1在相应第一环绕结构单元内为固定值。 The nanocrystal according to claim 2, wherein the alloy composition of the first surrounding structural unit is Cd _x1 Zn _{1 - x1} Se _y1 S _{1 - y1} , wherein 0 ≤ _x1 ≤ ₁ , 0 ≤ _y1 ≤ 1, and x1 and y1 are not 0 at the same time and 1 at the same time, and x1 and y1 are fixed values in the corresponding first surrounding structural unit.
根据权利要求2所述的纳米晶体，其特征在于，所述第二环绕结构单元的合金组分为Cd_x2Zn_1‐x2Se_y2S_1‐y2，其中0≤x2≤1，0≤y2≤1，并且x2和y2不同时为0和不同时为1。The nanocrystal according to claim 2, wherein the alloy composition of the second surrounding structural unit is Cd _x2 Zn _{1 - x 2} Se _y2 S _{1 - y2} , wherein 0 ≤ x2 ≤ ₁ , 0 ≤ _y2 ≤ 1, and x2 and y2 are not 0 at the same time and 1 at the same time.
根据权利要求3所述的纳米晶体，其特征在于，所述中心结构单元中，A点的合金组分为Cd_x0 ^AZn_1‐x0 ^ASe_y0 ^AS_1‐y0 ^A和，B点的合金组分为Cd_x0 ^BZn_1‐x0 ^BSe_y0 ^BS_1‐y0 ^B，其中A点相对于B点更靠近纳米晶体中心，且A点和B点的组成满足：_x0 ^A＞_x0 ^B，_y0 ^A＞_y0 ^B。The nanocrystal according to claim 3, wherein in the central structural unit, the alloy composition of point A is Cd _x0 ^A Zn _{1 - x0} ^A Se _y0 ^A S _{1 - y0} ^A and an alloy of point B The composition is Cd _x0 ^B Zn _1‐x0 ^B Se _y0 ^B S _1‐y0 ^B , where point A is closer to the center of the nanocrystal relative to point B, and the composition of points A and B satisfies: _x0 ^A > _x0 ^B , _y0 ^A > _y0 ^B .
根据权利要求5所述的纳米晶体，其特征在于，所述第二环绕结构单元中，C点的合金组分为Cd_x2 ^CZn_1‐x2 ^CSe_y2 ^CS_1‐y2 ^C，D点的合金组分为Cd_x2 ^DZn_1‐x2 ^DSe_y2 ^DS_1‐y2 ^D；其中C点相对于D点更靠近纳米晶体中心，C点和D点的组成满足：_x2 ^C＞_x2 ^D，_y2 ^C＞_y2 ^D。The nanocrystal according to claim 5, wherein in the second surrounding structural unit, the alloy component of the C point is Cd _x2 ^C Zn _{1 -x2} ^C Se _y2 ^C S _1‐y2 ^C , point D The alloy composition is Cd _x2 ^D Zn _1‐x2 ^D Se _y2 ^D S _1‐y2 ^D ; where point C is closer to the center of the nanocrystal relative to point D, and the composition of point C and point D satisfies: _x2 ^C > _x2 ^D , _y2 ^C > _y2 ^D .
根据权利要求1所述的纳米晶体，其特征在于，所述量子点结构单元包含2‐20层的单原子层，或者所述量子点结构单元包含1‐10层的晶胞层。The nanocrystal according to claim 1, wherein the quantum dot structural unit comprises a 2-20 layer monoatomic layer, or the quantum dot structural unit comprises a 1-10 layer cell layer.
根据权利要求8所述的纳米晶体，其特征在于，在径向方向上相邻的渐变合金组分结构的量子点结构单元交界处的两个单原子层之间形成连续合金组分结构，或者在径向方向上相邻的渐变合金组分结构的量子点结构单元交界处的两个晶胞层之间形成连续合金组分结构。The nanocrystal according to claim 8, wherein a continuous alloy composition structure is formed between two monoatomic layers at a junction of quantum dot structure units adjacent to a graded alloy composition structure in a radial direction, or A continuous alloy composition structure is formed between the two unit cell layers at the junction of the quantum dot structure units adjacent to the graded alloy composition structure in the radial direction.
根据权利要求1所述的纳米晶体，其特征在于，所述第一环绕结构单元和第二环绕结构单元在径向方向上交替分布。The nanocrystal according to claim 1, wherein the first surrounding structural unit and the second surrounding structural unit are alternately distributed in a radial direction.
根据权利要求10所述的纳米晶体，其特征在于，处于纳米晶体最外层的环绕结构单元为第二环绕结构单元。The nanocrystal according to claim 10, wherein the surrounding structural unit at the outermost layer of the nanocrystal is a second surrounding structural unit.
根据权利要求1所述的纳米晶体，其特征在于，所述纳米晶体的发光峰波长范围为400纳米至700纳米。The nanocrystal according to claim 1, wherein the nanocrystal has an emission peak wavelength ranging from 400 nm to 700 nm.
根据权利要求1所述的纳米晶体，其特征在于，所述纳米晶体的发光峰的半高峰宽为12纳米至80纳米。The nanocrystal according to claim 1, wherein the half peak width of the luminescence peak of the nanocrystal is from 12 nm to 80 nm.
一种如权利要求1所述的纳米晶体的制备方法，其特征在于，包括步骤：A method of preparing a nanocrystal according to claim 1, wherein the package Steps:

在预定位置处合成第一种化合物；Synthesizing the first compound at a predetermined position;

在第一种化合物的表面合成第二种化合物，所述第一种化合物与所述第二种化合物的合金组分相同或不同；Forming a second compound on the surface of the first compound, the first compound being the same or different from the alloy composition of the second compound;

使第一种化合物和第二种化合物体之间发生阳离子交换反应形成纳米晶体，所述纳米晶体的发光峰波长出现交替的蓝移和不变。A cation exchange reaction occurs between the first compound and the second compound to form nanocrystals having alternating blue shifts and constant wavelengths of luminescence peaks.
根据权利要求14所述的纳米晶体的制备方法，其特征在于，所述第一种化合物和/或所述第二种化合物的阳离子前驱体包括Zn的前驱体，所述Zn的前驱体为二甲基锌、二乙基锌、醋酸锌、乙酰丙酮锌、碘化锌、溴化锌、氯化锌、氟化锌、碳酸锌、氰化锌、硝酸锌、氧化锌、过氧化锌、高氯酸锌、硫酸锌、油酸锌或硬脂酸锌中的至少一种。The method for preparing a nanocrystal according to claim 14, wherein the cation precursor of the first compound and/or the second compound comprises a precursor of Zn, and the precursor of the Zn is two Methyl zinc, diethyl zinc, zinc acetate, zinc acetylacetonate, zinc iodide, zinc bromide, zinc chloride, zinc fluoride, zinc carbonate, zinc cyanide, zinc nitrate, zinc oxide, zinc peroxide, high At least one of zinc chlorate, zinc sulfate, zinc oleate or zinc stearate.
根据权利要求14所述的纳米晶体的制备方法，其特征在于，所述第一种化合物和/或所述第二种化合物的阳离子前驱体包括Cd的前驱体，所述Cd的前驱体为二甲基镉、二乙基镉、醋酸镉、乙酰丙酮镉、碘化镉、溴化镉、氯化镉、氟化镉、碳酸镉、硝酸镉、氧化镉、高氯酸镉、磷酸镉、硫酸镉、油酸镉或硬脂酸镉中的至少一种。The method for preparing a nanocrystal according to claim 14, wherein the cationic precursor of the first compound and/or the second compound comprises a precursor of Cd, and the precursor of the Cd is two Methyl cadmium, diethyl cadmium, cadmium acetate, cadmium acetylacetonate, cadmium iodide, cadmium bromide, cadmium chloride, cadmium fluoride, cadmium carbonate, cadmium nitrate, cadmium oxide, cadmium perchlorate, cadmium phosphate, sulfuric acid At least one of cadmium, cadmium oleate or cadmium stearate.
根据权利要求14所述的纳米晶体的制备方法，其特征在于，所述第一种化合物和/或所述第二种化合物的阴离子前驱体包括Se的前驱体，所述Se的前驱体为Se‐TOP、Se‐TBP、Se‐TPP、Se‐ODE、Se‐OA、Se‐ODA、Se‐TOA、Se‐ODPA或Se‐OLA中的至少一种。The method for preparing a nanocrystal according to claim 14, wherein the anion precursor of the first compound and/or the second compound comprises a precursor of Se, and the precursor of the Se is Se At least one of ‐TOP, Se‐TBP, Se‐TPP, Se‐ODE, Se‐OA, Se‐ODA, Se‐TOA, Se‐ODPA or Se‐OLA.
根据权利要求14所述的纳米晶体的制备方法，其特征在于，所述第一种化合物和/或所述第二种化合物的阴离子前驱体包括S的前驱体，所述S的前驱体为S‐TOP、S‐TBP、S‐TPP、S‐ODE、S‐OA、S‐ODA、S‐TOA、S‐ODPA、S‐OLA或烷基硫醇中的至少一种。The method for preparing a nanocrystal according to claim 14, wherein the anion precursor of the first compound and/or the second compound comprises a precursor of S, and the precursor of the S is S At least one of ‐TOP, S‐TBP, S‐TPP, S‐ODE, S‐OA, S‐ODA, S‐TOA, S‐ODPA, S‐OLA or alkyl mercaptan.
根据权利要求14所述的纳米晶体的制备方法，其特征在于，所述第一种化合物和/或第二种化合物的阴离子前驱体包括Te的前驱体，所述 Te的前驱体为Te‐TOP、Te‐TBP、Te‐TPP、Te‐ODE、Te‐OA、Te‐ODA、Te‐TOA、Te‐ODPA或Te‐OLA中的至少一种。The method for preparing a nanocrystal according to claim 14, wherein the anion precursor of the first compound and/or the second compound comprises a precursor of Te, The precursor of Te is at least one of Te‐TOP, Te‐TBP, Te‐TPP, Te‐ODE, Te‐OA, Te‐ODA, Te‐TOA, Te‐ODPA or Te‐OLA.
根据权利要求14所述的纳米晶体的制备方法，其特征在于，在加热条件下使第一种化合物和第二种化合物体之间发生阳离子交换反应。The method of producing a nanocrystal according to claim 14, wherein a cation exchange reaction occurs between the first compound and the second compound under heating.
根据权利要求20所述的纳米晶体的制备方法，其特征在于，加热温度在100℃至400℃之间。The method of producing nanocrystals according to claim 20, wherein the heating temperature is between 100 ° C and 400 ° C.
根据权利要求20所述的纳米晶体的制备方法，其特征在于，加热时间在2s至24h之间。The method of preparing nanocrystals according to claim 20, wherein the heating time is between 2 s and 24 h.
根据权利要求14所述的纳米晶体的制备方法，其特征在于，在合成第一种化合物时，阳离子前驱体与阴离子前驱体的摩尔比为100:1到1:50之间。The method for preparing a nanocrystal according to claim 14, wherein a molar ratio of the cationic precursor to the anionic precursor is between 100:1 and 1:50 in synthesizing the first compound.
根据权利要求14所述的纳米晶体的制备方法，其特征在于，在合成第二种化合物时，阳离子前驱体与阴离子前驱体的摩尔比为100:1到1:50之间。The method for preparing a nanocrystal according to claim 14, wherein a molar ratio of the cationic precursor to the anionic precursor is between 100:1 and 1:50 in synthesizing the second compound.
一种半导体器件，其特征在于，包括如权利要求1～13任一项所述的纳米晶体。A semiconductor device comprising the nanocrystal according to any one of claims 1 to 13.
根据权利要求25所述的半导体器件，其特征在于，所述半导体器件为电致发光器件、光致发光器件、太阳能电池、显示器件、光电探测器、生物探针以及非线性光学器件中的任意一种。 The semiconductor device according to claim 25, wherein said semiconductor device is any one of an electroluminescence device, a photoluminescence device, a solar cell, a display device, a photodetector, a bioprobe, and a nonlinear optical device. One.