CN211318270U

CN211318270U - Spin detector

Info

Publication number: CN211318270U
Application number: CN201922235015.7U
Authority: CN
Inventors: 刘威; 肖绍铸; 何少龙
Original assignee: Ningbo Institute of Material Technology and Engineering of CAS
Current assignee: Ningbo Institute of Material Technology and Engineering of CAS
Priority date: 2019-12-13
Filing date: 2019-12-13
Publication date: 2020-08-21
Anticipated expiration: 2029-12-13

Abstract

The utility model discloses a spin detector. The spin detector comprises at least one detection unit, the detection unit comprises a spin light emitting diode and a photoelectric amplification converter, and the photoelectric amplification converter is matched with the spin light emitting diode and at least used for capturing polarized light generated by the spin light emitting diode and forming the captured polarized light into an electric signal. The utility model provides a spin emitting diode and rather than complex photoelectricity amplification converter can make integrated array as the micro-scale basic detection unit, because the use of numerous micro-scale detection unit, spin photoelectron is improved greatly by the efficiency of surveying to can realize the collection of high quality spin angular resolution photoelectron energy spectrum in relatively very short time, show the collection efficiency who improves the electron energy spectrum, and then can improve the utilization ratio of expensive equipment greatly.

Description

Spin detector

Technical Field

The utility model particularly relates to a spin detector belongs to semiconductor device technical field.

Background

Spin detector for spin-resolved angle-resolved photoelectron spectroscopy: the electron spin detectors currently used in spin-resolved angle-resolved photoelectron spectroscopy mainly include a Motto-type spin detector, a very low energy electron diffraction detector (VLEEDdetector) and a diffusion interference detector, and the main principle of these spin detectors is to utilize the direction and spin dependence of the probability that spin-polarized electrons are scattered (or reflected) by a metal target, i.e., to utilize the asymmetry of the probability that spin-polarized electrons are scattered. Because the metal has free electron gas, the spinning photoelectrons are easily interfered by the free electrons in the metal target in the interaction of the spinning photoelectrons and the metal target, and the efficiency of forming effective detection signals is very low; in the multi-channel spin detector, the detection unit cannot be integrated on a large scale, so that the detection efficiency is not improved much, and the measurement time of the spin angle resolution photoelectron spectrum is too long. For example, the photoelectron detection efficiency of the conventional Motto type detector is only 0.1%, and the detection efficiency of the highest multi-channel detector can only reach 20%, so that the detection time is too long and the efficiency is low.

SUMMERY OF THE UTILITY MODEL

The main object of the present invention is to provide a spin detector to overcome the disadvantages of the prior art.

For realizing the purpose of the utility model, the utility model discloses a technical scheme include:

the embodiment of the utility model provides a spin detector, it includes at least one detection unit, detection unit includes spin emitting diode, photoelectric amplification converter and can spin emitting diode and photoelectric amplification converter between the reflection module of conduction circular polarized light, photoelectric amplification converter can be with the warp reflection module leading-in circular polarized light conversion forms the signal of telecommunication.

Further, the reflection module includes a metal reflection layer.

Furthermore, the material of the metal reflecting layer comprises aluminum and the like.

Preferably, the thickness of the metal reflective layer is 50 to 200 nm.

Still further, the reflective module further includes a sacrificial layer carrier on which the metal layer is disposed.

Further, the photoelectric amplification converter comprises a circularly polarized light detector and a charge coupled device, and the circularly polarized light detector is arranged on the charge coupled device.

Further, the photoelectric amplification converter and the spin light-emitting diode are integrally arranged into a whole.

Furthermore, the reflection module is arranged above the photoelectric amplification converter, and the spin light-emitting diode is arranged on one side of the photoelectric amplification converter and the reflection module.

Furthermore, the spin light-emitting diode comprises a GaAs spacing layer, an InGaAs quantum well or quantum dot layer, a GaAs buffer layer and a GaAs layer which are sequentially stacked.

Furthermore, the spin detector comprises a detection array composed of a plurality of detection units, and a metal isolation layer is arranged between every two adjacent detection units and at least used for preventing polarized light in one detection unit from entering the other detection unit.

Preferably, the material of the metal isolation layer includes aluminum and the like.

Preferably, the thickness of the metal isolation layer is 50-200 nm.

Further, the detection unit and the metal isolation layer are disposed on a semiconductor substrate.

The embodiment of the utility model provides a spin angle resolution photoelectron spectrometer is still provided, it includes spin detector.

Further, the spin detector is disposed at an exit position of an electron energy analyzer of the spin angle-resolved photoelectron spectrometer, replacing an original MCP (micro channel plate) for detecting photoelectrons.

Compared with the prior art, the utility model provides a spin emitting diode and rather than the compatible semiconductor technology of complex photoelectricity amplification converter can make integrated array as the micro-scale basic detecting element, because numerous micro-scale detecting element's use, spin photoelectron is improved greatly by the efficiency of surveying to can realize the collection of high quality spin angular resolution photoelectron spectroscopy in relatively very short time, show the collection efficiency who improves the electron spectroscopy, and then can improve the utilization ratio of expensive equipment greatly.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic diagram of a detection unit in a spin detector according to an exemplary embodiment of the present invention;

FIG. 2 is a schematic diagram of a detection array in a spin detector according to an exemplary embodiment of the present invention;

fig. 3 is a schematic structural diagram of a spin angle resolving photoelectron spectrometer according to an exemplary embodiment of the present invention;

description of reference numerals: 1-InGaAs quantum well or quantum dot layer, 2-GaAs layer, 3-GaAs buffer layer, 4-GaAs layer, 5-GaAs spacer layer, 6-spin polarized photoelectron, 7-cavity, 8-spin polarized photoelectron and cavity, 9-inclined surface of sacrificial layer carrier, 10-metal layer, 11-cavity prepared by micromachining process, 12-circularly polarized light detector, 13-CCD detector, 14-spin detection unit 15-metal wall, 16-semiconductor substrate, 17-incident light, 18-sample, 19-electronic lens module capable of realizing angle (momentum) resolution, 20-hemispherical electronic energy analyzer, 21-spin detector and 22-photoelectron operation track.

Detailed Description

In view of the deficiencies in the prior art, the inventor of the present invention has made extensive studies and practices to provide the technical solution of the present invention. The technical solution, its implementation and principles, etc. will be further explained as follows.

Spin light emitting diode: the spin-polarized electrons or holes enter the quantum wells of the spin light-emitting diode through the electrodes and recombine with the non-spin-polarized holes or electrons in the quantum wells to generate photons, and the device generates circularly polarized light in different directions due to the fact that the spin-polarized carriers and the non-spin-polarized carriers have different heavy degeneracy states. The spin direction of spin-polarized electrons or holes corresponds to the direction of circularly polarized light generated, which can be referred to as Fiederling, R., et al, Objection and detection of a spin-polarized current in light-emitting diode Nature,1999.402(6763): p.787-790.

Angle-resolved photoelectron spectroscopy: the angle-resolved photoelectron spectrometer is a scientific instrument for measuring the electronic energy band structure of a single crystal sample; photons of sufficient energy (the light source can be a gas discharge light source such as a helium lamp, a laser or a synchrotron radiation light source, etc.) are utilized to interact with a sample through the photoelectric effect to generate photoelectrons, and energy and momentum information (namely an electron band structure) of electrons in the crystal material can be obtained according to energy conservation and momentum conservation by measuring the energy and momentum of the photoelectrons.

The spin angle resolution photoelectron spectrometer measures the spin direction of electrons on the basis of measuring the momentum and energy of the electrons, thereby forming a spin angle resolution photoelectron spectrum, being capable of distinguishing energy bands occupied by the electrons in different spin directions and having important and deeper understanding on the electronic structure of a sample.

The embodiment of the utility model provides a spin emitting diode is the semiconductor material device, and spin polarized carrier keeps the unchangeable distance of movement of spin direction than longer in the semiconductor, and spin emitting diode's theory of operation is, and spin polarized electron (the utility model discloses in for spin polarized photoelectron) pours into the quantum well or the quantum dot that have certain ground state energy, and from the non-spin polarized hole of opposite side electrode pouring into, can with spin polarized electron recombination luminescence, produce different levogyration or dextrorotation circular polarized light. A plurality of spin light emitting diodes can be manufactured into an array by using an integrated process, and left-handed or right-handed circularly polarized light generated by the diodes can be detected by a photoelectric amplification converter on one side, so that an electric signal is formed.

Referring to fig. 1 and 2, a spin detector according to an exemplary embodiment of the present invention includes a plurality of detecting units 14 disposed on a semiconductor substrate 16, the detecting units 14 forming a detecting array, and a metal isolation layer (or referred to as a partition wall) 15 disposed between two adjacent detecting units 14, the metal isolation layer at least preventing polarized light in one detecting unit from entering another detecting unit; each of the detecting units 14 is a micro-sized detecting unit, the size of the detecting unit 14 is determined by the used integration process, especially the process of manufacturing the charge coupled device, for example, the size of the detecting unit 14 may be 15 × 5 micrometers, and other micro-sized detecting units may be manufactured according to specific situations.

Specifically, a semiconductor integration process may be used to fabricate a plurality of mutually isolated detection units on a semiconductor substrate, a Reactive Ion Etching (RIE) process may be used to fabricate a trench between two adjacent detection units, and a metal layer may be deposited in the trench to form a metal isolation layer, where the metal isolation layer may be made of metal such as aluminum, and the thickness of the metal isolation layer is 50-200 nm.

Specifically, referring to fig. 2 again, the detecting unit 14 includes a spin light emitting diode, a photoelectric amplification converter, and a reflection module, the reflection module is disposed between the spin light emitting diode and the photoelectric amplification converter and is capable of transmitting circularly polarized light between the spin light emitting diode and the photoelectric amplification converter, the photoelectric amplification converter is capable of converting circularly polarized light generated by the spin light emitting diode into an electrical signal, wherein the reflection module is disposed above the photoelectric amplification converter and distributed on the same side, and the spin light emitting diodes are disposed side by side on the same side of the reflection module and the photoelectric amplification converter.

The spin light emitting diode comprises a GaAs spacing layer 5, an InGaAs quantum well or quantum dot layer 1, a GaAs layer 4, a GaAs buffer layer 3 and a GaAs layer 2 which are sequentially stacked, the photoelectric amplification converter comprises a circularly polarized light detector (the structure of the circularly polarized light detector can refer to the device structure disclosed in CN 103954363B) 12 and a charge coupling element (namely a CCD detector) 13, and the circularly polarized light detector 12 is arranged on the charge coupling element 13; the reflection module comprises a metal reflection layer 10, the metal reflection layer 10 is arranged on the inclined plane 9 of a sacrificial layer carrier, namely the metal reflection layer 10 is obliquely arranged between the spin light-emitting diode and the photoelectric amplification converter, wherein the metal reflection layer 10 can be an aluminum layer with the thickness of 50-200nm or the like.

Specifically, the spin light emitting diode, the photoelectric amplification converter and the reflection module are arranged side by side, the reflection module is located above the photoelectric amplification converter, the circularly polarized light detector is located above the CCD detector in the photoelectric amplification converter, and circularly polarized light generated from the spin light emitting diode is refracted by the reflection module, enters the circularly polarized light detector, and then enters the CCD detector.

Specifically, the photoelectric amplification converter can be integrated with a spin light-emitting diode to form an integrated device for light emission and detection.

Specifically, the preparation process of the spin detector can comprise the following steps: firstly, a semiconductor thin film integration process is used for simultaneously preparing a spin light-emitting diode, a CCD detector, an integrated circularly polarized light detector and a transparent sacrificial layer carrier, then a micro-machining process (such as Reactive Ion Etching (RIE) or anisotropic corrosion) is used for machining a bevel 9 on the sacrificial layer carrier, and a metal reflecting layer 10 is manufactured on the bevel, wherein a structure 11 shown in figure 1 is a cavity formed when the sacrificial layer carrier is prepared by the micro-machining process, and has no specific function on the function of the spin detector, and when other machining processes are adopted for manufacturing, the cavity 11 cannot be formed; the steps of manufacturing a spin light emitting diode are described in (Ohno, y., et al., electrical injection in a magnetic semiconductor device heterojunction. nature,1999.402(6763): p.790-792), in which incident spin photoelectrons and holes recombine in InGaAs quantum well layers to generate circularly polarized light.

The working principle of the spin detector provided by the exemplary embodiment of the present invention includes that the spin light emitting diode receives the photoelectrons 6 with incident spin polarization, and generates corresponding left-handed or right-handed circularly polarized light in the quantum well layer 1 according to the spin of the spin polarized photoelectrons upwards or downwards, and the left-handed or right-handed circularly polarized light enters the photoelectric amplification converter composed of the circularly polarized light detector 12 and the CCD detector 13 through the refraction of the metal reflective layer 10; in the photoelectric amplification converter, left-handed or right-handed circularly polarized light is modulated by a circularly polarized light detector to present different local field light intensity distributions, and can be collected by a CCD detector, so that incident spin photoelectron signals are converted into electric signals.

As shown in fig. 3, the embodiment of the present invention provides a spin detector which can be applied to a spin angular resolution photoelectron spectrometer, the spin detector for detecting the spin state of incident spin photoelectrons based on an integrated spin light emitting diode can be installed at the exit of an electron energy analyzer of the angular resolution photoelectron spectrometer, and replaces the original MCP (micro channel plate) to detect the spin information of photoelectrons, the photoelectrons have been resolved on energy and momentum when moving to a spin detection array, and the spin detection array can form the spin-resolved angular resolution photoelectron spectrum after obtaining the spin information of photoelectrons; in the spin angle-resolved photoelectron spectrometer shown in fig. 3, 17 is incident light, 18 is a sample, 19 is an electron lens module capable of achieving angle (momentum) resolution, 20 is a hemispherical electron energy analyzer, 21 is a spin detector, and 22 is a photoelectron travel locus; of course, the spin detector provided by the embodiment of the present invention can also be applied to other optoelectronic devices or other apparatuses, and will not be described herein again.

Wherein, the embodiment of the utility model provides an in such as spin emitting diode based on quantum well or quantum dot and the usable traditional semiconductor technology integrated preparation of photoelectric amplification converter that needs to its array unit number that can constitute will be more than present multichannel detector greatly, thereby improves the detection efficiency of photoelectron, makes measuring time greatly reduced.

The utility model provides a spin detector for spin angle resolution photoelectron spectrometer based on spin emitting diode has solved the shortcoming that current spin detector detection efficiency is low, and a plurality of spin emitting diode can utilize integrated technology to make certain unit array, and the levogyration that the diode produced or dextrorotation circular polarized light can be surveyed through the photoelectric amplification converter of one side to form the signal of telecommunication, and photoelectric amplification converter can be integrated jointly with spin emitting diode, form luminous and the integration device who surveys.

The utility model provides a spin emitting diode and rather than the compatible semiconductor technology of complex photoelectric amplification converter can make integrated array as the micro-scale basic detection unit, because numerous micro-scale detection unit's use, spin photoelectron is improved greatly by the efficiency of surveying to can realize the collection of high quality spin angular resolution photoelectron spectroscopy in relatively very short time, show the collection efficiency who improves the electron spectroscopy, and then can improve the utilization ratio of expensive equipment greatly.

It should be understood that the above-mentioned embodiments are merely illustrative of the technical concepts and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and to implement the present invention, and therefore, the protection scope of the present invention should not be limited thereby. All equivalent changes and modifications made according to the spirit of the present invention should be covered by the protection scope of the present invention.

Claims

1. A spin detector is characterized by comprising at least one detection unit, wherein the detection unit comprises a spin light-emitting diode, a photoelectric amplification converter and a reflection module capable of conducting circularly polarized light between the spin light-emitting diode and the photoelectric amplification converter, and the photoelectric amplification converter can convert the circularly polarized light introduced by the reflection module into an electric signal.

2. A spin detector as claimed in claim 1, wherein: the reflective module includes a metal reflective layer.

3. A spin detector as claimed in claim 2, wherein: the thickness of the metal reflecting layer is 50-200 nm.

4. A spin detector as claimed in claim 2, wherein: the reflective module further includes a sacrificial layer carrier on which the metallic reflective layer is disposed.

5. A spin detector as claimed in claim 2, wherein: the photoelectric amplification converter comprises a circularly polarized light detector and a charge coupled element, and the circularly polarized light detector is arranged on the charge coupled element.

6. A spin detector as claimed in claim 5, wherein: the photoelectric amplification converter and the spin light-emitting diode are integrally arranged into a whole.

7. A spin detector as claimed in claim 5, wherein: the reflection module is arranged above the photoelectric amplification converter, and the spin light-emitting diode is arranged on one side of the photoelectric amplification converter and the reflection module.

8. A spin detector as claimed in claim 1, wherein: the spin light-emitting diode comprises a GaAs spacing layer, an InGaAs quantum well or quantum dot layer, a GaAs buffer layer and a GaAs layer which are sequentially stacked.

9. A spin detector according to any of claims 1 to 8, comprising a detector array comprising a plurality of said detector cells, a metal spacer layer being provided between two adjacent detector cells, said metal spacer layer being at least adapted to prevent polarized light in one detector cell from entering another detector cell.

10. A spin detector as claimed in claim 9, wherein: the thickness of the metal isolation layer is 50-200 nm.

11. A spin detector as claimed in claim 9, wherein: the detection unit and the metal isolation layer are disposed on a semiconductor substrate.