An AlGaN-based cation vacancy defect single-photon emission source and its preparation method

Abstract

The preparation method of the AlGaN-based cation vacancy defect single-photon emission source of the present invention belongs to the fields of semiconductor technology and quantum information technology. Through group theory analysis combined with first-principles calculations, it is confirmed that the neutral cation vacancy of AlGaN is suitable for single-photon emission. The specific implementation includes the following key steps: p-type AlGaN growth, preparation of cation vacancies by surface electron irradiation, pulsed laser irradiation and other methods combined with nitridation treatment and thermal annealing treatment. The present invention also provides an AlGaN-based cation vacancy defect single-photon emission source prepared by the above method. The present invention provides an optional single-photon source solution for the field of quantum communication, and at the same time has guiding significance for the design of single-photon sources based on semiconductor material defects. The process is simple, the industrial preparation method of the semiconductor material AlGaN on which it is based is mature, the photon energy is suitable for low-loss propagation in optical fibers, and it has broad application prospects.

Description

Technical Field

[0001] The present invention belongs to the fields of semiconductor technology and quantum information technology, and is an AlGaN-based cation vacancy defect single-photon emission source and a preparation method thereof. Background Art

[0002] Quantum bits are core components of technologies such as quantum information encoding and quantum communication. Photons are ideal quantum bits because they can propagate over long distances, interact weakly with the environment, and can be manipulated within a linear optical framework. There are many systems suitable for single-photon emission, such as single atoms, quantum dots, and color centers in semiconductors. Although these single-photon emission systems use different materials, they primarily rely on similar principles based on two-level systems. Among them, color centers in semiconductors are a type of defect structure in semiconductor materials that can emit light. They can generate single-photon sources at room temperature and have great practical value.

[0003] The research on single photon sources based on bulk semiconductor materials currently mainly includes NV in diamond - 、SiV - , GeV - 、SnV - , V in silicon carbide Si V C - 、V Si - Their emission wavelengths are mostly in the visible light region, and due to the large fiber propagation losses, they are not suitable for direct use in long-distance quantum communication. In recent years, the wide-bandgap III-nitride AlGaN has been extensively studied in the field of optoelectronic devices. Its corresponding material growth technology has matured, making large-scale material preparation possible. However, there is no relevant method to realize single-photon sources based on AlGaN. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a method for preparing an AlGaN-based cation vacancy defect single-photon emission source and an AlGaN-based cation vacancy defect single-photon emission source prepared by the method.

[0005] To achieve the above object, the present invention provides a method for preparing an AlGaN-based cation vacancy defect single-photon emission source, comprising the following steps:

[0006] S1: Demonstrate that the energy levels of electrically neutral cation vacancy defects in AlGaN are suitable for single-photon emission;

[0007] S2: Growth of p-type doped AlGaN material;

[0008] S3: introducing cation vacancy defects into the p-type doped AlGaN material;

[0009] S4: nitriding treatment to compensate for nitrogen vacancies;

[0010] S5: In order to decompose the Mg-H bond and activate the p-type doping, an annealing treatment is performed at 500-1000°C for 10-30 minutes in a nitrogen atmosphere to adjust the Fermi level to a position where electrically neutral cation vacancies are stably present, thereby obtaining an AlGaN material containing electrically neutral cation vacancies.

[0011] Preferably, sp is established around the cation vacancy in S1. 3 The dangling bond Hamiltonian is diagonalized to obtain the local eigenstates. The local electron filling configuration is analyzed according to group theory methods, and the local energy level position is determined by combining density functional first-principles numerical calculations.

[0012] Preferably, the growth method in S2 is MOCVD, the growth substrate is a sapphire substrate, the p-type doping method is superlattice doping or polarization induced doping, and the p-type doping concentration is 1×10 17 cm -3 .

[0013] Preferably, the method of introducing cation vacancy defects in S3 is to -1 ~10 -5 The p-type doped AlGaN material is subjected to electron irradiation or pulsed laser irradiation under high vacuum conditions of the order of Pa to avoid the introduction of other element impurities.

[0014] Preferably, the nitridation treatment in S4 is: using NH3 or N2H4 as a nitrogen source at a temperature of 500-1000°C and a low nitrogen source flow rate of 1000-5000 sccm to improve the p-type doping efficiency by compensating for nitrogen vacancies.

[0015] The present invention also provides an AlGaN-based cation vacancy defect single-photon emission source prepared by the above method.

[0016] The advantages of the present invention using the above technical solution are:

[0017] The present invention discloses a method for preparing an AlGaN-based cation vacancy defect single-photon emission source. Based on a p-type AlGaN material preparation process, the cation vacancy defect is prepared by subsequent electron irradiation or pulsed laser, nitridation treatment, and high-temperature annealing. The p-type doped AlGaN ensures that the cation vacancy is in an electronic configuration in an electrically neutral state, and theoretical calculations show that the corresponding cation vacancy defect energy level is suitable for infrared single-photon emission. The present invention enables the preparation of a single-photon source based on the wide-bandgap Group III nitride AlGaN, provides an optional single-photon source solution for the field of quantum communication, and has guiding significance for the design of single-photon sources based on semiconductor material defects. The preparation process is simple, the industrial preparation method of the semiconductor material AlGaN on which it is based is mature, the photon energy is suitable for low-loss propagation in optical fibers, and the method has broad application prospects.

[0018] The AlGaN-based cation vacancy defect single-photon emission source of the present invention utilizes the large band gap width of the group III nitride AlGaN and the high dangling bond energy level of the nitrogen element, utilizes cation vacancies to realize defect energy levels completely located inside the band gap, and adjusts the defect electron configuration to an electrically neutral state by regulating the Fermi level to achieve single-photon emission of transitions between single spin channel defect energy levels, and the emitted photon energy level is located in the infrared band. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 This is a schematic diagram of the single-photon emission process of neutral cation vacancies in AlGaN materials;

[0021] Figure 2 GaN, Al 0.25 Ga 0.75 N, Al 0.5 Ga 0.5 N, Al 0.8 Ga 0.2 Relationship between the cation vacancy formation energy in N and AlN and the Fermi level (dashed lines correspond to the band gaps of the corresponding components). DETAILED DESCRIPTION

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] By screening host semiconductor materials within the same main group for a specific electronic structure, we achieve the theoretical design of single-photon sources and the theoretical prediction of the single-photon emission band. This theoretical design principle is conceptually clear, and screening the entire main group of elements ensures that no single-photon emission sources that meet the requirements are missed.

[0024] The present invention provides a method for preparing an AlGaN-based cation vacancy defect single-photon emission source, comprising the following steps:

[0025] S1: Demonstrate that the energy levels of electrically neutral cation vacancy defects in AlGaN are suitable for single-photon emission;

[0026] S2: Growth of p-type doped AlGaN material;

[0027] S3: introducing cation vacancy defects into the p-type doped AlGaN material;

[0028] S4: nitriding treatment to compensate for nitrogen vacancies;

[0029] S5: In order to decompose the Mg-H bond and activate the p-type doping, an annealing treatment is performed at 500-1000°C for 10-30 minutes in a nitrogen atmosphere to adjust the Fermi level to a position where electrically neutral cation vacancies exist, thereby obtaining an AlGaN material containing electrically neutral cation vacancies.

[0030] The sp surrounding the cation vacancy in S1 is established 3 The dangling bond Hamiltonian is diagonalized to obtain the local eigenstates, and the local electron filling configuration is analyzed according to the group theory method. The local energy level position is determined by combining the density functional first principle numerical calculation. Figure 1 The figure shows a schematic diagram of the single-photon emission process of neutral cation vacancies in AlGaN materials. Using group theory analysis combined with first-principles calculations, it is demonstrated that the defect energy level of a spin channel of the neutral cation vacancy in AlGaN is located within the band gap, and the defect energy level transition in the dotted box can achieve single-photon emission.

[0031] Figure 2 is the cation vacancy formation energy of AlGaN with different Al compositions, among which the neutral cation vacancy can stably exist when the Fermi level is near the top of the valence band, indicating that the p-type doping of AlGaN material meets the requirements for realizing neutral cation vacancies.

[0032] The growth method in S2 is MOCVD, the growth substrate is sapphire substrate, and the p-type doping method is superlattice doping or polarization induced doping. Too low or too high Fermi level may lead to instability of neutral cation vacancies. The p-type doping concentration should be at a moderate level, such as 1×10 17 cm -3 Since p-type doping of AlGaN is relatively difficult, theoretical analysis shows that neutral cation vacancies can maintain the same properties in AlN, GaN, and AlGaN structures. Therefore, the use of p-type doping techniques, such as those based on AlN or GaN superlattices or polarization-induced doping, can improve the p-type doping efficiency and adjust the Fermi level to a position where neutral cation vacancies can exist stably.

[0033] The method of introducing cationic vacancy defects in S3 is to irradiate the p-type doped AlGaN material with electrons or pulsed lasers under high vacuum conditions. The atomic structure of the vacancy defect color center is simple and easy to control experimentally, and no impurities of different elements are introduced during the preparation process. -1 ~10 -5 Electron irradiation or pulsed laser irradiation is carried out under high vacuum conditions of the Pa level in order to avoid serious degradation of material quality, and the irradiation energy is controlled at the keV level.

[0034] The nitridation treatment in S4 is as follows: using NH3 or N2H4 as a nitrogen source at a temperature of 500-1000°C and a low nitrogen source flow rate of 1000-5000sccm to improve the p-type doping efficiency by compensating for nitrogen vacancy donor defects.

[0035] The high-temperature annealing treatment in S5 activates p-type doping and adjusts the Fermi level to achieve thermodynamic stabilization of neutral cation vacancies in AlGaN.

[0036] The present invention also provides an AlGaN-based cation vacancy defect single-photon emission source prepared by the above method.

[0037] The advantages of the present invention using the above technical solution are:

[0038] The present invention discloses a method for preparing an AlGaN-based cation vacancy defect single-photon emission source. Based on a p-type AlGaN material preparation process, the cation vacancy defect is prepared by subsequent electron irradiation or pulsed laser, nitridation treatment, and high-temperature annealing. The p-type doped AlGaN ensures that the cation vacancy is in an electronic configuration in an electrically neutral state, and theoretical calculations show that the corresponding cation vacancy defect energy level is suitable for infrared single-photon emission. The present invention enables the preparation of a single-photon source based on the wide-bandgap Group III nitride AlGaN, provides an optional single-photon source solution for the field of quantum communication, and has guiding significance for the design of single-photon sources based on semiconductor material defects. The preparation process is simple, the industrial preparation method of the semiconductor material AlGaN on which it is based is mature, the photon energy is suitable for low-loss propagation in optical fibers, and the method has broad application prospects.

[0039] The AlGaN-based cation vacancy defect single-photon emission source of the present invention utilizes the large band gap width of the group III nitride AlGaN and the high dangling bond energy level of the nitrogen element, utilizes cation vacancies to realize defect energy levels completely located inside the band gap, and adjusts the defect electron configuration to an electrically neutral state by regulating the Fermi level to achieve single-photon emission of transitions between single spin channel defect energy levels, and the emitted photon energy level is located in the infrared band.

[0040] The material for achieving single photon emission based on the specific electronic configuration of vacancy defects proposed in the present invention is not limited to AlGaN. In short, the protection scope of the present invention should include those obvious changes, substitutions and modifications to those skilled in the art.

Claims

1. A method for preparing an AlGaN-based cation vacancy defect single-photon emission source, characterized in that: The following steps are involved: S1: Demonstrate that the energy levels of electrically neutral cation vacancy defects in AlGaN are suitable for single-photon emission; S2: Growth of p-type doped AlGaN material; S3: introducing cation vacancy defects into the p-type doped AlGaN material; S4: nitriding treatment to compensate for nitrogen vacancies; S5: To decompose the Mg-H bond and activate the p-type doping, an annealing treatment is performed at 500-1000°C for 10-30 minutes in a nitrogen atmosphere to adjust the Fermi level to a position where electrically neutral cation vacancies are stably present, thereby obtaining an AlGaN material containing electrically neutral cation vacancies. Among them, the method of introducing cation vacancy defects in S3 is to -1 ~10 -5 The p-type doped AlGaN material is subjected to electron irradiation or pulsed laser irradiation under high vacuum conditions of the order of Pa to avoid the introduction of other element impurities.

2. The method for preparing an AlGaN-based cation vacancy defect single-photon emission source according to claim 1, wherein: The sp surrounding the cation vacancy in S1 is established 3 The dangling bond Hamiltonian is diagonalized to obtain the local eigenstates. The local electron filling configuration is analyzed according to group theory methods, and the local energy level position is determined by combining density functional first-principles numerical calculations.

3. The method for preparing an AlGaN-based cation vacancy defect single-photon emission source according to claim 1, wherein: The growth method in S2 is MOCVD, the growth substrate is sapphire substrate, the p-type doping method is superlattice doping or polarization induced doping, and the p-type doping concentration is 1×10 17 cm -3 .

4. The method for preparing an AlGaN-based cation vacancy defect single-photon emission source according to claim 1, wherein: The nitridation treatment in S4 is as follows: using NH3 or N2H4 as a nitrogen source at a temperature of 500-1000°C and a low nitrogen source flow rate of 1000-5000sccm to improve the p-type doping efficiency by compensating for nitrogen vacancies.

5. An AlGaN-based cation vacancy defect single-photon emission source prepared by the method according to any one of claims 1 to 4.

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