CN111354856A - Quantum dot light-emitting diode - Google Patents
Quantum dot light-emitting diode Download PDFInfo
- Publication number
- CN111354856A CN111354856A CN201811583525.7A CN201811583525A CN111354856A CN 111354856 A CN111354856 A CN 111354856A CN 201811583525 A CN201811583525 A CN 201811583525A CN 111354856 A CN111354856 A CN 111354856A
- Authority
- CN
- China
- Prior art keywords
- layer
- quantum dot
- dot light
- electrode
- hole
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K50/00—Organic light-emitting devices
- H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
- H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
- H10K50/115—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers comprising active inorganic nanostructures, e.g. luminescent quantum dots
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K50/00—Organic light-emitting devices
- H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
- H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
- H10K50/125—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers specially adapted for multicolour light emission, e.g. for emitting white light
- H10K50/13—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers specially adapted for multicolour light emission, e.g. for emitting white light comprising stacked EL layers within one EL unit
- H10K50/131—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers specially adapted for multicolour light emission, e.g. for emitting white light comprising stacked EL layers within one EL unit with spacer layers between the electroluminescent layers
Landscapes
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Crystallography & Structural Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Nanotechnology (AREA)
- Electroluminescent Light Sources (AREA)
Abstract
The invention discloses a quantum dot light emitting diode, which comprises: a first electrode, a second electrode, a hole generation layer disposed between the first electrode and the second electrode; the first quantum dot light-emitting layer is arranged between the first electrode and the hole generating layer, and the first electronic function layer is arranged between the first electrode and the first quantum dot light-emitting layer; the second quantum dot light-emitting layer is arranged between the second electrode and the hole generating layer, and the second electronic function layer is arranged between the second electrode and the second quantum dot light-emitting layer. The quantum dot light-emitting diode provided by the invention can work normally under alternating current, and the quantum dot light-emitting diode can emit various monochromatic light, white light and colored light, thereby meeting the requirements of various industries.
Description
Technical Field
The invention relates to the field of quantum dot light-emitting devices, in particular to a quantum dot light-emitting diode.
Background
Due to the unique optical properties of quantum dots, such as continuously adjustable light-emitting wavelength with size and composition, narrow light-emitting spectrum, high fluorescence efficiency, good stability, etc., quantum dot-based electroluminescent diodes have been widely focused and studied in the display and lighting fields. With the continuous development of quantum dot light emitting diodes, the performance of the quantum dot light emitting diodes is steadily improved, and the quantum dot light emitting diodes show great application prospects.
The quantum dot light-emitting diode is a direct current drive device, has a rectification characteristic, can normally work under the drive of a stable direct current signal source, and the electricity consumption in actual life is usually 220V/50Hz alternating current, so the quantum dot light-emitting diode cannot normally work under the environment. In order to enable the quantum dot light-emitting diode to work normally, a high-performance alternating current-direct current conversion device needs to be additionally arranged in a driving system of the quantum dot light-emitting diode, so that not only is the complexity of system integration increased, but also the energy loss in the alternating current-direct current conversion process can increase the power consumption, and the quantum dot light-emitting diode is not beneficial to energy conservation and environmental protection.
Accordingly, the prior art is yet to be improved and developed.
Disclosure of Invention
In view of the above-mentioned shortcomings of the prior art, the present invention provides a quantum dot light emitting diode capable of operating under alternating current, which can emit various monochromatic lights or alternatively emit colored lights and white lights, and meets different needs of various fields.
The technical scheme of the invention is as follows:
a quantum dot light emitting diode, comprising: a first electrode, a second electrode, a hole generation layer disposed between the first electrode and the second electrode; the first quantum dot light-emitting layer is arranged between the first electrode and the hole generating layer, and the first electronic function layer is arranged between the first electrode and the first quantum dot light-emitting layer; the second quantum dot light-emitting layer is arranged between the second electrode and the hole generating layer, and the second electronic function layer is arranged between the second electrode and the second quantum dot light-emitting layer.
A quantum dot light emitting diode, comprising: a first electrode, a second electrode, an electron generation layer disposed between the first electrode and the second electrode; the first quantum dot light-emitting layer is arranged between the first electrode and the electron generation layer, and the first hole function layer is arranged between the first electrode and the first quantum dot light-emitting layer; the second quantum dot light-emitting layer is arranged between the second electrode and the electron generation layer, and the second hole function layer is arranged between the second electrode and the second quantum dot light-emitting layer.
Has the advantages that: the quantum dot light-emitting diode provided by the invention can work normally under alternating current, and the quantum dot light-emitting diode can emit various monochromatic light, white light and colored light, thereby meeting the requirements of various industries.
Drawings
Fig. 1 is a schematic structural diagram of a quantum dot light emitting diode according to an embodiment of the present invention.
FIG. 2a is a schematic structural view of a heterojunction charge generation layer of a p-n-p structure as a hole generation layer.
FIG. 2b is a schematic diagram of an energy level structure of a heterojunction charge generation layer of a p-n-p structure as a hole generation layer.
Fig. 3a is a schematic diagram of the working mechanism of a quantum dot light-emitting diode based on a p-n-p heterojunction charge generation layer as a hole generation layer under the action of an alternating positive electric field.
FIG. 3b is a schematic diagram of the working mechanism of a quantum dot light-emitting diode based on a p-n-p heterojunction charge generation layer as a hole generation layer under the action of an alternating negative electric field.
Fig. 4 is another schematic structural diagram of a quantum dot light emitting diode according to an embodiment of the present invention.
FIG. 5a is a schematic structural view of an n-p-n heterojunction charge generation layer as an electron generation layer.
FIG. 5b is a schematic diagram of an energy level structure of an n-p-n heterojunction charge generation layer as an electron generation layer.
Fig. 6a is a schematic diagram of the working mechanism of a quantum dot light-emitting diode based on an n-p-n heterojunction charge generation layer as an electron generation layer under the action of an alternating positive electric field.
FIG. 6b is a schematic diagram of the working mechanism of a quantum dot light-emitting diode based on an n-p-n heterojunction charge generation layer as an electron generation layer under the action of an alternating negative electric field.
Detailed Description
The present invention provides a quantum dot light emitting diode, and the present invention will be described in further detail below in order to make the objects, technical solutions, and effects of the present invention clearer and clearer. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The existing quantum dot light emitting layer is a direct current driving type device, has a rectification characteristic, and can normally work only under the driving of a stable direct current signal source but can not normally work under the condition of alternating current. In order to enable the quantum dot light emitting layer to work normally, a high-performance alternating current-direct current conversion device needs to be additionally arranged in a driving system of the quantum dot light emitting layer, so that not only is the complexity of system integration increased, but also the energy loss in the alternating current-direct current conversion process can increase the power consumption, and the quantum dot light emitting layer is not beneficial to energy conservation and environmental protection. Based on this, the embodiment of the invention provides the quantum dot light-emitting layer capable of being driven by alternating current, which can be better compatible with actual electricity utilization and reduce power consumption.
Specifically, the quantum dot light emitting diode provided by the embodiment of the present invention includes: a first electrode, a second electrode, a hole generation layer disposed between the first electrode and the second electrode; the first quantum dot light-emitting layer is arranged between the first electrode and the hole generating layer, and the first electronic function layer is arranged between the first electrode and the first quantum dot light-emitting layer; the second quantum dot light-emitting layer is arranged between the second electrode and the hole generating layer, and the second electronic function layer is arranged between the second electrode and the second quantum dot light-emitting layer.
The first electron function layer may be one or both of a first electron injection layer and a first electron transport layer, and when the first electron function layer is one or both of the first electron injection layer and the first electron transport layer, the first electron transport layer is disposed close to the first quantum dot light emitting layer; the second electron function layer may be one or both of a second electron injection layer and a second electron transport layer, and when the second electron function layer is one or both of the second electron injection layer and the second electron transport layer, the second electron transport layer is disposed near the second quantum dot light emitting layer.
The following description will be made in detail by taking the quantum dot light emitting diode shown in fig. 1 as an example, as shown in fig. 1, the quantum dot light emitting diode sequentially includes, from bottom to top: the organic light-emitting diode comprises a substrate 101, a first electrode 102, a first electron transport layer 103, a first quantum dot light-emitting layer 104, a hole generation layer 105, a second quantum dot light-emitting layer 106, a second electron transport layer 107 and a second electrode 108.
In a preferred embodiment, the first electron transport layer material and the second electron transport layer material may be electron transport materials commonly used in the field of organic light emitting diodes/quantum dot light emitting diodes, including organic electron transport materials such as: TPBi, BCP, Bphen, TmPyPb, B3PYMPM, etc.; and inorganic electron transport materials such as: TiO 22ZnO, etc.; and combinations of the above organic/inorganic electron transport materials. In a preferred embodiment, the thickness of each of the first electron transport layer and the second electron transport layer is 10 to 100 nm. It should be noted that the first electron transport layer material and the second electron transport layer material may be the same or different; the thickness of the first electron transport layer and the thickness of the second electron transport layer may be the same or different.
In a preferred embodiment, the first and second quantum dot light emitting layer materials may be group II-VI compound semiconductors such as CdSe or ZnCdS or CdSeS or ZnCdSeS or CdSe/ZnS or CdSeS/ZnS or CdSe/CdS/ZnS or ZnCdS/ZnS or CdS/ZnS or ZnCdSeS/ZnS, etc.; may be a group III-V compound semiconductor such as GaAs or GaN or InP/ZnS or the like; may be a group I-III-VI compound semiconductor such as CuInS or AgInS or CuInS/ZnS or AnInS/ZnS or the like; may be a group IV elemental semiconductor such as Si or C or Graphene (Graphene), etc.; may be perovskite quantum dots. In a preferred embodiment, the thickness of each of the first quantum dot light emitting layer and the second quantum dot light emitting layer may be 5 to 100 nm. It should be noted that the material of the first quantum dot light-emitting layer and the material of the second quantum dot light-emitting layer may be the same or different; the thickness of the first quantum dot light-emitting layer and the thickness of the second quantum dot light-emitting layer can be the same or different.
In this embodiment, the first quantum dot light emitting layer and the second quantum dot light emitting layer may be made of the same material or the same color material, so that the quantum dot light emitting diode emits monochromatic light under the driving of an alternating current, for example: red, green, blue, etc.; or two materials with different colors, the quantum dot light-emitting diode emits colored light under the drive of alternating current, wherein when the blue light is combined with yellow light and the period of the alternating current is less than the resolution limit time of human eyes, the quantum dot light-emitting diode shows white light.
In a preferred embodiment, the hole generating layer material is a p-type doped hole transport material. More preferably, the dopant of the doped hole transport material is selected from the group consisting of F4-TCNQ, MoO3、WO3And HAT-CN, etc., doped with the above-mentioned dopant to finally obtain a p-type doped hole transport material. More preferably, the hole transport material is selected from one or more of NPB, TCTA, and the like. Even more preferably, the dopant of the doped hole transport material is F4-TCNQ, and the hole transport material is NPB; or, the dopant of the doped hole transport material is HAT-CN, and the hole transport material is NPB; or, the dopant of the doped hole transport material is HAT-CN, and the hole transport material is TCTA.
In a preferred embodiment, the hole generation layer can be formed by two back-to-back p-n heterojunction charge generation layers, i.e., the hole generation layer is a p-n-p heterojunction charge generation layer, as shown in fig. 2a, wherein 201 is a p-type material layer, 202 is an n-type material layer, and 203 is a p-type material layer. Fig. 2b is a schematic diagram of the energy level structure of the p-n-p heterojunction charge generation layer, where 211 is the energy level of the p-type material layer, 212 is the energy level of the n-type material layer, and 213 is the energy level of the p-type material layer. More preferably, the p-n-p heterogeneous charge generation layer may be TCTA/HAT-CN/TCTA, NPB/HAT-CN/NPB, CBP/MoO3/CBP 、CuPc/C60CuPc, etc.
In a preferred embodiment, the hole generating layer material may also be a transparent conductive polymer with a high work function, such as: PEDOT: PSS, etc.
In a preferred embodiment, the thickness of the hole generation layer may be 5 to 50 nm.
In a preferred embodiment, the dopant of the doped hole transport material is present in an amount of 0.5% to 5% by mass of the material of the hole generating layer to ensure a sufficient number of holes in the hole generating layer.
In this embodiment, the working mechanism of the ac-driven quantum dot light emitting diode is as follows: fig. 3a shows a working mechanism of a quantum dot light emitting diode with a p-n-p heterojunction charge generating layer as a hole generating layer under the action of an ac positive electric field, where 301 is an energy level of a first electrode, 302 is an energy level of a first electron transport layer, 303 is an energy level of a first quantum dot light emitting layer, 3041 is an energy level of a p-type material layer in the p-n-p heterojunction charge generating layer, 3042 is an energy level of an n-type material layer in the p-n-p heterojunction charge generating layer, 3043 is an energy level of a p-type material layer in the p-n-p heterojunction charge generating layer, 305 is an energy level of a second quantum dot light emitting layer, 306 is an energy level of a second electron transport layer, and 307 is an energy level of a second electrode. In a half period when the alternating current is positive, as shown in fig. 3a, the first electrode is used as an anode, the second electrode is used as a cathode, and at this time, a heterojunction formed by the first electron transport layer, the first quantum dot light emitting layer and the hole generating layer from the first electrode to the hole generating layer is in a reverse bias state and does not work; and a heterojunction formed by the hole generation layer, the second quantum dot light-emitting layer and the second electron transmission layer from the hole generation layer to the second electrode is in a forward bias state, and is in a conduction state after an applied voltage is larger than a built-in electric field of the heterojunction formed by the hole generation layer, the second quantum dot light-emitting layer and the second electron transmission layer. Under the action of an electric field from the first electrode to the second electrode, electrons in an n-p heterojunction in the p-n-p heterojunction charge generation layer are transited from the HOMO energy level of the p-type material layer to the LUMO energy level of the n-type material layer, holes are generated in the p-type material layer, and the holes move towards the second electrode under the action of an external electric field; on the other hand, the electrons move from the second electrode to the hole generating layer, and the electrons meet in the second quantum dot light emitting layer and then are recombined to emit light.
Fig. 3b shows a schematic diagram of the working mechanism of the quantum dot light emitting diode with the p-n-p heterojunction charge generation layer as the hole generation layer under the action of an ac negative electric field, where 311 is the energy level of the first electrode, 312 is the energy level of the first electron transport layer, 313 is the energy level of the first quantum dot light emitting layer, 3141 is the energy level of the p-type material layer in the p-n-p heterojunction charge generation layer, 3142 is the energy level of the n-type material layer in the p-n-p heterojunction charge generation layer, 3143 is the energy level of the p-type material layer in the p-n-p heterojunction charge generation layer, 315 is the energy level of the second quantum dot light emitting layer, 316 is the energy level of the second electron transport layer, and 317 is the energy level of the second electrode. In the half period that the alternating current is negative, as shown in fig. 3b, the first electrode is a cathode, the second electrode is an anode, and a heterojunction formed by the hole generation layer from the hole generation layer to the second electrode, the second quantum dot light-emitting layer and the second electron transport layer is in reverse bias and does not work; a heterojunction formed by a hole generation layer from the hole generation layer to the first electrode, the first quantum dot light-emitting layer and the first electron transmission layer is in a forward bias state, electrons in a p-n heterojunction in the heterojunction charge generation layer p-n-p can jump from a HOMO energy level of a p-type material layer to a LUMO energy level of an n-type material layer, holes are generated in the p-type material layer, and the holes can move towards the first electrode under the action of an external electric field; on the other hand, the electrons move from the first electrode to the hole generation layer, and the electrons meet in the first quantum dot light emitting layer and then are recombined to emit light.
In this embodiment, the amplitude of the alternating current may affect the light emitting intensity, the light emitting spectrum, and the color coordinate of the quantum dot light emitting diode.
In this embodiment, the period of the alternating current may affect the light emitting effect of the quantum dot light emitting diode. For example: if the two quantum dot light emitting layers of the quantum dot light emitting diode are respectively a blue substance and a yellow substance, when the period of the alternating current is decreased from large to small, the light emitting of the quantum dot light emitting diode is gradually changed from blue light/yellow light which is changed by alternative flickering into continuous white light.
The quantum dot light emitting diode of the present invention will be described in detail by way of examples.
Example 1:
taking a transparent conductive thin film ITO with the thickness of 50nm as a first electrode;
depositing ZnO nanoparticles on a first electrode by a solution method to serve as a first electron transport layer, wherein the thickness of the first electron transport layer is 40 nm;
depositing CdSe/ZnS quantum dots on the first electron transport layer by a solution method to serve as a first quantum dot light-emitting layer, wherein the thickness of the first quantum dot light-emitting layer is 25 nm;
co-depositing HAT-CN doped TCTA as a hole generation layer on the first quantum dot light-emitting layer by using an evaporation method, wherein the thickness of the hole generation layer is 20 nm;
depositing CdSe/ZnS quantum dots on the hole generation layer by a solution method to serve as a second quantum dot light-emitting layer, wherein the thickness of the second quantum dot light-emitting layer is 25 nm;
depositing ZnO nanoparticles on the second quantum dot light-emitting layer by using a solution method to form a second electron transmission layer, wherein the thickness of the second electron transmission layer is 40 nm;
and depositing Al on the second electron transport layer by using an evaporation method to serve as a second electrode, wherein the thickness of the second electrode is 120 nm.
Example 2:
taking a transparent conductive thin film ITO with the thickness of 50nm as a first electrode;
depositing ZnO nanoparticles on a first electrode by a solution method to serve as a first electron transport layer, wherein the thickness of the first electron transport layer is 40 nm;
depositing CdSe/ZnS quantum dots on the first electron transport layer by a solution method to serve as a first quantum dot light-emitting layer, wherein the thickness of the first quantum dot light-emitting layer is 25 nm;
depositing TCTA/HAT-CN/TCTA as a hole generation layer on the first quantum dot light-emitting layer by an evaporation method in sequence, wherein the thickness of the hole generation layer is 30 nm;
depositing CdSe/ZnS quantum dots on the hole generation layer by a solution method to serve as a second quantum dot light-emitting layer, wherein the thickness of the second quantum dot light-emitting layer is 25 nm;
depositing ZnO nanoparticles on the second quantum dot light-emitting layer by using a solution method to form a second electron transmission layer, wherein the thickness of the second electron transmission layer is 40 nm;
and depositing Al on the second electron transport layer by using an evaporation method to serve as a second electrode, wherein the thickness of the second electrode is 120 nm.
Example 3:
taking a transparent conductive thin film ITO with the thickness of 50nm as a first electrode;
depositing ZnO nanoparticles on a first electrode by a solution method to serve as a first electron transport layer, wherein the thickness of the first electron transport layer is 40 nm;
solution deposition of CsPbBr on the first electron-transport layer3The quantum dots are used as a first quantum dot light-emitting layer, and the thickness of the first quantum dot light-emitting layer is 25 nm;
PSS is used as a hole generation layer, and the thickness of the hole generation layer is 20 nm;
solution deposition of CsPbBr on hole-generating layer3The quantum dots are used as a second quantum dot light-emitting layer, and the thickness of the second quantum dot light-emitting layer is 25 nm;
depositing ZnO nanoparticles on the second quantum dot light-emitting layer by using a solution method to form a second electron transmission layer, wherein the thickness of the second electron transmission layer is 40 nm;
and depositing Al on the second electron transport layer by using an evaporation method to serve as a second electrode, wherein the thickness of the second electrode is 120 nm.
Example 4:
taking a transparent conductive thin film ITO with the thickness of 50nm as a first electrode;
depositing ZnO nanoparticles on a first electrode by a solution method to serve as a first electron transport layer, wherein the thickness of the first electron transport layer is 40 nm;
depositing yellow quantum dots CuInS/ZnS on the first electron transport layer by a solution method to serve as a first quantum dot light-emitting layer, wherein the thickness of the first quantum dot light-emitting layer is 30 nm;
depositing TCTA/HAT-CN/TCTA as a hole generation layer on the first quantum dot light-emitting layer by an evaporation method in sequence, wherein the thickness of the hole generation layer is 30 nm;
depositing blue quantum dots ZnCdS/ZnS on the hole generation layer by a solution method to serve as a second quantum dot light-emitting layer, wherein the thickness of the second quantum dot light-emitting layer is 25 nm;
depositing ZnO nanoparticles on the second quantum dot light-emitting layer by using a solution method to form a second electron transmission layer, wherein the thickness of the second electron transmission layer is 40 nm;
and depositing Al on the second electron transport layer by using an evaporation method to serve as a second electrode, wherein the thickness of the second electrode is 120 nm.
The quantum dot light-emitting diode provided by the embodiment of the invention comprises: a first electrode, a second electrode, an electron generation layer disposed between the first electrode and the second electrode; the first quantum dot light-emitting layer is arranged between the first electrode and the electron generation layer, and the first hole function layer is arranged between the first electrode and the first quantum dot light-emitting layer; the second quantum dot light-emitting layer is arranged between the second electrode and the electron generation layer, and the second hole function layer is arranged between the second electrode and the second quantum dot light-emitting layer.
The first hole function layer may be one or both of a first hole injection layer and a first hole transport layer, and when the first hole function layer is one or both of the first hole injection layer and the first hole transport layer, the first hole transport layer is disposed close to the first quantum dot light emitting layer; the second hole function layer may be one or both of a second hole injection layer and a second hole transport layer, and when the second hole function layer is one or both of the second hole injection layer and the second hole transport layer, the second hole transport layer is disposed near the second quantum dot light emitting layer.
The following description will be made in detail by taking the quantum dot light emitting diode shown in fig. 4 as an example, as shown in fig. 4, the quantum dot light emitting diode sequentially includes, from bottom to top: the organic light emitting diode comprises a substrate 401, a first electrode 402, a first hole transport layer 403, a first quantum dot light emitting layer 404, an electron generating layer 405, a second quantum dot light emitting layer 406, a second hole transport layer 407 and a second electrode 408.
In a preferred embodiment, the first hole transport layer material and the second hole transport layer material may be both hole transport materials commonly used in the field of organic light emitting diodes/quantum dot light emitting diodes, including organic hole transport materials such as: Poly-TPD, TFB, PVK, TCTA, NPB, TAPC, CBP, mCP, etc.; and inorganic hole transport materials such as: NiO and the like; and combinations of the above organic/inorganic hole transport materials. In a preferred embodiment, the thickness of each of the first hole transport layer and the second hole transport layer is 10 to 100 nm. It should be noted that the first hole transport layer material and the second hole transport layer material may be the same or different; the thickness of the first hole transport layer and the thickness of the second hole transport layer can be the same or different.
In this embodiment, the materials selected for the first quantum dot light emitting layer and the second quantum dot light emitting layer are described above, and are not described herein again.
In a preferred embodiment, the electron generation layer material is an n-type doped electron transport material. More preferably, the dopant of the doped electron transport material is selected from one or more of alkali metals and salts of alkali metals, etc., for example: li, Na, Cs2CO3And the electron transport material is doped with the dopant, so that the n-type doped electron transport material can be obtained finally. The electron transport material can be an electron transport material commonly used in the field of organic light emitting diodes/quantum dot light emitting diodes.
In a preferred embodiment, the electron generation layer can be formed by two back-to-back n-p heterojunction charge generation layers, i.e. the electron generation layer is an n-p-n heterojunction charge generation layer, as shown in fig. 5a, wherein 501 is an n-type material layer, 502 is a p-type material layer, and 503 is an n-type material layer. Fig. 5b is a schematic diagram of the energy level structure of the n-p-n heterojunction charge generation layer, where 511 is the energy level of the n-type material layer, 512 is the energy level of the p-type material layer, and 513 is the energy level of the n-type material layer. More preferably, the n-p-n heterojunction charge generation layer may be C60/CuPc/C60And ZnO/PEDOT, PSS/ZnO, ZnO/Graphene/ZnO, and the like. In a preferred embodiment, the thickness of the electron generation layer may be 10 to 100 nm.
In a preferred embodiment, the dopant of the doped electron transport material is present in an amount of 0.5 to 5% by mass of the material of the electron generation layer to ensure a sufficient number of electrons in the electron generation layer.
In this embodiment, the working mechanism of the ac-driven quantum dot light emitting diode is as follows: fig. 6a shows a schematic diagram of the operation mechanism of a quantum dot light emitting diode with an n-p-n heterojunction charge generation layer as an electron generation layer under the action of an ac positive electric field, where 601 is the energy level of the first electrode, 602 is the energy level of the first hole injection layer, 603 is the energy level of the first hole transport layer, 604 is the energy level of the first quantum dot light emitting layer, 6051 is the energy level of the n-type material layer in the n-p-n heterojunction charge generation layer, 6052 is the energy level of the p-type material layer in the n-p-n heterojunction charge generation layer, 6053 is the energy level of the n-type material layer in the n-p-n heterojunction charge generation layer, 606 is the energy level of the second quantum dot light emitting layer, 607 is the energy level of the second hole transport layer, 608 is the energy level of the second hole injection layer, and 609 is the energy level of the second electrode. In a half period in which the alternating current is positive, as shown in fig. 6a, the first electrode serves as an anode, the second electrode serves as a cathode, and at this time, a heterojunction formed by the electron generation layer, the second quantum dot light-emitting layer and the second hole transport layer from the electron generation layer to the second electrode is in a reverse bias state and does not work; and a heterojunction formed by the first hole transport layer, the first quantum dot light-emitting layer and the electron generation layer from the first electrode to the electron generation layer is in a forward bias state, and is in a conduction state after an applied voltage is larger than a built-in electric field of the heterojunction formed by the first hole transport layer, the first quantum dot light-emitting layer and the electron generation layer. Under the action of an electric field from the first electrode to the second electrode, electrons in a p-n heterojunction in the n-p-n heterojunction charge generation layer are transited from the HOMO energy level of the p-type material layer to the LUMO energy level of the n-type material layer, electrons are generated in the n-type material layer, and the electrons move towards the first electrode under the action of an external electric field; on the other hand, the holes move from the first electrode to the electron generation layer, and the holes meet in the first quantum dot light emitting layer and then are recombined to emit light.
As shown in fig. 6b, the working mechanism of the quantum dot light emitting diode with the n-p-n heterojunction charge generation layer as the electron generation layer under the action of the ac negative electric field is schematically illustrated, wherein 611 is the energy level of the first electrode, 612 is the energy level of the first hole injection layer, 613 is the energy level of the first hole transport layer, 614 is the energy level of the first quantum dot light emitting layer, 6151 is the energy level of the n-type material layer in the n-p-n heterojunction charge generation layer, 6152 is the energy level of the p-type material layer in the n-p-n heterojunction charge generation layer, 6153 is the energy level of the n-type material layer in the n-p-n heterojunction charge generation layer, 616 is the energy level of the second quantum dot light emitting layer, 617 is the energy level of the second hole transport layer, 618 is the energy level of the second hole injection layer, and 619 is the energy level of the second electrode. In the half period when the alternating current is negative, as shown in fig. 6b, the first electrode is used as a cathode, the second electrode is used as an anode, and at this time, a heterojunction formed by the first hole transport layer, the first quantum dot light emitting layer and the electron generating layer from the first electrode to the electron generating layer is in a reverse bias state and does not work; the heterojunction from the electron generation layer to the second electrode, the second quantum dot light-emitting layer and the second hole transmission layer is in a forward bias state, electrons in the p-n heterojunction in the n-p-n heterojunction charge generation layer jump from the HOMO energy level of the p-type material layer to the LUMO energy level of the n-type material layer, electrons capable of moving freely are generated in the n-type material layer, and the electrons move towards the second electrode under the action of an external electric field; on the other hand, the holes move from the second electrode to the electron generation layer, and the holes meet in the second quantum dot light emitting layer and then are recombined to emit light.
In this embodiment, the amplitude of the alternating current may affect the light emitting intensity, the light emitting spectrum, and the color coordinate of the quantum dot light emitting diode.
In this embodiment, the period of the alternating current may affect the light emitting effect of the quantum dot light emitting diode. For example: if the two quantum dot light emitting layers of the quantum dot light emitting diode are respectively a blue substance and a yellow substance, when the period of the alternating current is decreased from large to small, the light emitting of the quantum dot light emitting diode is gradually changed from blue light/yellow light which is changed by alternative flickering into continuous white light.
The quantum dot light emitting diode of the present invention will be described in detail below with reference to examples.
Example 1:
taking a transparent conductive thin film ITO with the thickness of 50nm as a first electrode;
PSS is used as a first hole injection layer, and the thickness of the first hole injection layer is 40 nm;
depositing TFB as a first hole transport layer on the first hole injection layer by using a solution method, wherein the thickness of the first hole transport layer is 30 nm;
depositing CdSe/ZnS quantum dots on the first hole transport layer by a solution method to serve as a first quantum dot light-emitting layer, wherein the thickness of the first quantum dot light-emitting layer is 25 nm;
depositing ZnO nanoparticles on the first quantum dot light-emitting layer by using a solution method to serve as a first hole blocking layer, wherein the thickness of the first hole blocking layer is 10 nm;
co-depositing Li-doped Bphen on the first hole blocking layer by using an evaporation method to serve as an electron generation layer, wherein the thickness of the electron generation layer is 20 nm;
depositing ZnO nanoparticles on the electron generation layer by a solution method to serve as a second hole blocking layer, wherein the thickness of the second hole blocking layer is 10 nm;
depositing CdSe/ZnS quantum dots on the second hole blocking layer by a solution method to serve as a second quantum dot light-emitting layer, wherein the thickness of the second quantum dot light-emitting layer is 25 nm;
depositing TCTA on the second quantum dot light-emitting layer by using an evaporation method to form a second hole transport layer, wherein the thickness of the second hole transport layer is 30 nm;
depositing MoO on the second hole transport layer by evaporation3As a second hole injection layer, the thickness of the second hole injection layer is 10 nm;
and depositing Al on the second hole injection layer by using an evaporation method to form a second electrode, wherein the thickness of the second electrode is 120 nm.
Example 2:
taking a transparent conductive thin film ITO with the thickness of 50nm as a first electrode;
PSS is used as a first hole injection layer, and the thickness of the first hole injection layer is 40 nm;
depositing TFB as a first hole transport layer on the first hole injection layer by using a solution method, wherein the thickness of the first hole transport layer is 30 nm;
depositing CdSe/ZnS quantum dots on the first hole transport layer by a solution method to serve as a first quantum dot light-emitting layer, wherein the thickness of the first quantum dot light-emitting layer is 25 nm;
depositing ZnO nanoparticles on the first quantum dot light-emitting layer by using a solution method to serve as a first hole blocking layer, wherein the thickness of the first hole blocking layer is 10 nm;
C60/CuPc/C60 are sequentially deposited on the first hole blocking layer by an evaporation method to serve as an electron generation layer, and the thickness of the electron generation layer is 30 nm;
depositing ZnO nanoparticles on the electron generation layer by a solution method to serve as a second hole blocking layer, wherein the thickness of the second hole blocking layer is 10 nm;
depositing CdSe/ZnS quantum dots on the second hole blocking layer by a solution method to serve as a second quantum dot light-emitting layer, wherein the thickness of the second quantum dot light-emitting layer is 25 nm;
depositing TCTA on the second quantum dot light-emitting layer by using an evaporation method to form a second hole transport layer, wherein the thickness of the second hole transport layer is 30 nm;
depositing MoO on the second hole transport layer by evaporation3As a second hole injection layer, the thickness of the second hole injection layer is 10 nm;
and depositing Al on the second hole injection layer by using an evaporation method to form a second electrode, wherein the thickness of the second electrode is 120 nm.
Example 3:
taking a transparent conductive thin film ITO with the thickness of 50nm as a first electrode;
PSS is used as a first hole injection layer, and the thickness of the first hole injection layer is 40 nm;
depositing TFB as a first hole transport layer on the first hole injection layer by using a solution method, wherein the thickness of the first hole transport layer is 30 nm;
depositing CdSe/ZnS quantum dots on the first hole transport layer by a solution method to serve as a first quantum dot light-emitting layer, wherein the thickness of the first quantum dot light-emitting layer is 25 nm;
sequentially depositing ZnO/PEDOT on the first quantum dot light-emitting layer by a solution method, wherein PSS/ZnO is used as an electron generation layer, and the thickness of the electron generation layer is 50 nm;
depositing CdSe/ZnS quantum dots on the electron generation layer by a solution method to serve as a second quantum dot light-emitting layer, wherein the thickness of the second quantum dot light-emitting layer is 25 nm;
depositing TCTA on the second quantum dot light-emitting layer by using an evaporation method to form a second hole transport layer, wherein the thickness of the second hole transport layer is 30 nm;
depositing MoO on the second hole transport layer by evaporation3As a second hole injection layer, the thickness of the second hole injection layer is 10 nm;
and depositing Ag on the second hole injection layer by using an evaporation method to form a second electrode, wherein the thickness of the second electrode is 120 nm.
Example 4:
taking a transparent conductive thin film ITO with the thickness of 50nm as a first electrode;
PSS is used as a first hole injection layer, and the thickness of the first hole injection layer is 40 nm;
depositing TFB as a first hole transport layer on the first hole injection layer by using a solution method, wherein the thickness of the first hole transport layer is 30 nm;
depositing CuInS/ZnS yellow quantum dots on the first hole transport layer by a solution method to serve as a first quantum dot light-emitting layer, wherein the thickness of the first quantum dot light-emitting layer is 15 nm;
sequentially depositing ZnO/PEDOT on the first quantum dot light-emitting layer by a solution method, wherein PSS/ZnO is used as an electron generation layer, and the thickness of the electron generation layer is 50 nm;
depositing ZnCdS/ZnS blue quantum dots on the electron generation layer by a solution method to serve as a second quantum dot light-emitting layer, wherein the thickness of the second quantum dot light-emitting layer is 25 nm;
depositing TCTA on the second quantum dot light-emitting layer by using an evaporation method to form a second hole transport layer, wherein the thickness of the second hole transport layer is 30 nm;
depositing MoO on the second hole transport layer by evaporation3As a second hole injection layer, the thickness of the second hole injection layer is 10 nm;
and depositing Ag on the second hole injection layer by using an evaporation method to form a second electrode, wherein the thickness of the second electrode is 120 nm.
In summary, the present invention provides a quantum dot light emitting diode. The quantum dot light-emitting diode provided by the invention can work normally under alternating current, and the quantum dot light-emitting diode can emit various monochromatic light, white light and colored light, thereby meeting the requirements of various industries.
It is to be understood that the invention is not limited to the examples described above, but that modifications and variations may be effected thereto by those of ordinary skill in the art in light of the foregoing description, and that all such modifications and variations are intended to be within the scope of the invention as defined by the appended claims.
Claims (11)
1. A quantum dot light emitting diode, comprising: a first electrode, a second electrode, a hole generation layer disposed between the first electrode and the second electrode; the first quantum dot light-emitting layer is arranged between the first electrode and the hole generating layer, and the first electronic function layer is arranged between the first electrode and the first quantum dot light-emitting layer; the second quantum dot light-emitting layer is arranged between the second electrode and the hole generating layer, and the second electronic function layer is arranged between the second electrode and the second quantum dot light-emitting layer.
2. The quantum dot light-emitting diode of claim 1, wherein the hole generation layer material is a p-type doped hole transport material.
3. The quantum dot light-emitting diode of claim 1, wherein the hole generation layer is a p-n-p heterojunction charge generation layer.
4. The quantum dot light-emitting diode of claim 1, wherein the hole generation layer material is a transparent conductive polymer.
5. The qd-led of claim 2, wherein the dopant of the doped hole transport material is selected from the group consisting of F4-TCNQ, MoO3、WO3And HAT-CN; and/or
The hole transport material is selected from one or more of NPB, NPB and TCTA, and/or
The mass percentage of the dopant of the doped hole transport material in the hole generation layer material is 0.5-5%.
6. The qd-led of claim 3, wherein the p-n-p heterojunction charge generation layer is TCTA/HAT-CN/TCTA, NPB/HAT-CN/NPB, CBP/MoO3(ii)/CBP or CuPc/C60(ii) CuPc; and/or
The first electrode is ITO, and the second electrode is at least one of Al or Ag; and/or
The first quantum dot light-emitting layer is CdSe, ZnCdS, CdSeS, ZnCdSeS, CdSe/ZnS, CdSeS/ZnS, CdSe/CdS/ZnS, ZnCdS/Zn, CdS/ZnS or ZnCdSeS/ZnS, GaAs or GaN or InP/ZnS, CuInS or AgInS or CuInS/ZnS or AnInS/ZnS, Si or C or graphene, the second quantum dot light-emitting layer is selected from at least one of the first quantum dot materials, and the second quantum dot light-emitting layer material is the same as or different from the first quantum dot light-emitting layer material.
7. A quantum dot light emitting diode, comprising: a first electrode, a second electrode, an electron generation layer disposed between the first electrode and the second electrode; the first quantum dot light-emitting layer is arranged between the first electrode and the electron generation layer, and the first hole function layer is arranged between the first electrode and the first quantum dot light-emitting layer; the second quantum dot light-emitting layer is arranged between the second electrode and the electron generation layer, and the second hole function layer is arranged between the second electrode and the second quantum dot light-emitting layer.
8. The qd-led of claim 7, wherein the electron generation layer material is an n-type doped electron transport material.
9. The qd-led of claim 7, wherein the electron generation layer is an n-p-n heterojunction charge generation layer.
10. The quantum dot light-emitting diode of claim 8, wherein the dopant of the doped electron transport material is selected from one or more of alkali metals and salts of alkali metals; and/or
The mass percentage of the dopant of the doped electron transport material in the material of the electron generation layer is 0.5-5%.
11. The quantum dot light-emitting diode of claim 9, wherein the n-p-n heterojunction charge generation layer is: c60/CuPc/C60And ZnO/PEDOT, PSS/ZnO, or ZnO/Graphene/ZnO; and/or
The first electrode is ITO, and the second electrode is at least one of Al or Ag; and/or
The first quantum dot light-emitting layer is CdSe, ZnCdS, CdSeS, ZnCdSeS, CdSe/ZnS, CdSeS/ZnS, CdSe/CdS/ZnS, ZnCdS/Zn, CdS/ZnS or ZnCdSeS/ZnS, GaAs or GaN or InP/ZnS, CuInS or AgInS or CuInS/ZnS or AnInS/ZnS, Si or C or graphene, the second quantum dot light-emitting layer is selected from at least one of the first quantum dot materials, and the second quantum dot light-emitting layer material is the same as or different from the first quantum dot light-emitting layer material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811583525.7A CN111354856A (en) | 2018-12-24 | 2018-12-24 | Quantum dot light-emitting diode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811583525.7A CN111354856A (en) | 2018-12-24 | 2018-12-24 | Quantum dot light-emitting diode |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111354856A true CN111354856A (en) | 2020-06-30 |
Family
ID=71196775
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811583525.7A Pending CN111354856A (en) | 2018-12-24 | 2018-12-24 | Quantum dot light-emitting diode |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111354856A (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105161629A (en) * | 2015-08-18 | 2015-12-16 | Tcl集团股份有限公司 | Alternating-current drive quantum dot light-emitting diode (QLED) and preparation method thereof |
| CN105244450A (en) * | 2015-10-09 | 2016-01-13 | 北京大学深圳研究生院 | Organic light-emitting device driven by alternating electric field and preparation method for organic light-emitting device |
| CN105514295A (en) * | 2016-02-29 | 2016-04-20 | 京东方科技集团股份有限公司 | Light emitting device, method for forming same and display device |
| CN106549111A (en) * | 2016-12-07 | 2017-03-29 | Tcl集团股份有限公司 | Exchange electrically driven (operated) light emitting diode with quantum dots, its preparation method and application |
| CN107623075A (en) * | 2017-09-22 | 2018-01-23 | 深圳市华星光电半导体显示技术有限公司 | Quantum light emitting diode and display device |
| CN107863445A (en) * | 2017-10-30 | 2018-03-30 | 武汉华美晨曦光电有限责任公司 | A kind of white light OLED device with exchange driving |
| CN109065746A (en) * | 2018-07-17 | 2018-12-21 | 华南理工大学 | A kind of forward and reverse luminous Organic Light Emitting Diode |
-
2018
- 2018-12-24 CN CN201811583525.7A patent/CN111354856A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105161629A (en) * | 2015-08-18 | 2015-12-16 | Tcl集团股份有限公司 | Alternating-current drive quantum dot light-emitting diode (QLED) and preparation method thereof |
| CN105244450A (en) * | 2015-10-09 | 2016-01-13 | 北京大学深圳研究生院 | Organic light-emitting device driven by alternating electric field and preparation method for organic light-emitting device |
| CN105514295A (en) * | 2016-02-29 | 2016-04-20 | 京东方科技集团股份有限公司 | Light emitting device, method for forming same and display device |
| CN106549111A (en) * | 2016-12-07 | 2017-03-29 | Tcl集团股份有限公司 | Exchange electrically driven (operated) light emitting diode with quantum dots, its preparation method and application |
| CN107623075A (en) * | 2017-09-22 | 2018-01-23 | 深圳市华星光电半导体显示技术有限公司 | Quantum light emitting diode and display device |
| CN107863445A (en) * | 2017-10-30 | 2018-03-30 | 武汉华美晨曦光电有限责任公司 | A kind of white light OLED device with exchange driving |
| CN109065746A (en) * | 2018-07-17 | 2018-12-21 | 华南理工大学 | A kind of forward and reverse luminous Organic Light Emitting Diode |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5302690B2 (en) | Organic optoelectronic devices | |
| CN101447555B (en) | Laminated organic electro-luminescent device of an organic semiconductor-based hetero-junction electric-charge generating layer taken as a connecting layer and preparation method thereof | |
| CN103904178A (en) | Quantum dot luminescent device | |
| CN106601919A (en) | Hybrid light emitting device, display panel and display device | |
| WO2019095565A1 (en) | Tandem quantum-dot light-emitting device, panel and display | |
| CN110212105B (en) | Quantum dot light-emitting device, preparation method thereof and lighting device | |
| KR20130008892A (en) | Quantum-dot light emitting diode and method for fabricating the same | |
| JP2020537338A (en) | Multi-layer quantum dot LED and its manufacturing method | |
| JP6965452B2 (en) | Quantum dot white light diode | |
| KR102081101B1 (en) | Quantum-dot light emitting diode | |
| Feng et al. | High efficiency non-doped white organic light-emitting diodes based on blue exciplex emission | |
| US20220278293A1 (en) | Organic electroluminescent device and array substrate | |
| CN109980105B (en) | QLED device | |
| Sun et al. | A color-tunable and high-effective organic light-emitting diode device with forward-inverse structure as intelligent lighting display | |
| CN110649170B (en) | Quantum dot light-emitting diode and manufacturing method thereof | |
| CN109390491A (en) | Light emitting diode and the preparation method and application thereof | |
| KR101450858B1 (en) | Organic electroluminescent device and fabracation method by using graphene oxide | |
| CN111354856A (en) | Quantum dot light-emitting diode | |
| TWI540779B (en) | Organic light-emitting device | |
| Xiao et al. | Trade-offs between illumination and modulation performances of quantum-dot LED | |
| CN208028089U (en) | Doping and undoped complementary type white light organic electroluminescent device | |
| CN112331783B (en) | AC driven light emitting device, preparation method thereof and light emitting device | |
| CN113130794A (en) | Quantum dot light-emitting diode and preparation method thereof | |
| CN112331787A (en) | Application of metal tetraphenylporphyrin complex in electron transport material, quantum dot light-emitting device and preparation method thereof, and light-emitting device | |
| CN112341606A (en) | Compound, preparation method thereof and quantum dot light-emitting diode |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200630 |
|
| RJ01 | Rejection of invention patent application after publication |