Deep ultraviolet photoelectric detector with ultra-wide bandgap semiconductor heterojunction structure
By employing an ultra-wide bandgap semiconductor heterojunction structure and optimized electrode materials, the stability and efficiency issues of traditional solar blind detectors have been resolved, achieving high-efficiency photoelectric conversion and stability under extreme environments, making it suitable for aerospace and other fields.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-02
- Publication Date
- 2026-03-17
AI Technical Summary
Traditional solar blind detectors suffer from drawbacks such as poor stability, low photoelectric conversion efficiency, low signal-to-noise ratio, low photoresponse current, and high cost.
An ultra-wide bandgap semiconductor heterojunction structure is adopted, including a substrate, a DBR layer, a Zn-doped β-Ga2O3 layer, a barrier layer, a Ga-doped γ-GeO2 layer, and a current collection layer to form a PN heterojunction. Combined with a distributed Bragg mirror and a graphene current collection layer, the electrode materials are optimized to improve photoelectric conversion efficiency and stability.
It improves photoelectric conversion efficiency, signal-to-noise ratio and photoresponse current, reduces cost, and remains stable in high-temperature or extreme environments, making it suitable for extreme applications such as aerospace.
Smart Images
Figure CN224007026U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of deep ultraviolet photodetector technology, and in particular to a deep ultraviolet photodetector with an ultrawide bandgap semiconductor heterojunction structure. Background Technology
[0002] Currently, solar blind detectors are detectors capable of detecting ultraviolet (UV) radiation. Their main principle is based on the sensitivity of semiconductor materials to UV light. When UV radiation strikes a semiconductor material, it generates charge pairs, leading to the flow of current. By measuring the magnitude of this current, the intensity of the UV radiation can be determined. As our understanding of the effects of UV radiation deepens, solar blind detectors are becoming increasingly important. Because they can overcome sunlight interference, they can detect UV radiation even under sunlight, making them a promising area for application. Therefore, developing higher-performance solar blind detectors is crucial.
[0003] The photoresponse current value also indirectly reflects the response speed. A higher photoresponse current usually corresponds to a faster carrier transport capability, thereby shortening the response time and enabling the detector to respond to the optical signal quickly in a short time.
[0004] However, traditional solar blind detectors suffer from drawbacks such as poor stability, poor photoelectric conversion efficiency, low signal-to-noise ratio, low photoresponse current, and high cost. Summary of the Invention
[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a deep ultraviolet photodetector with an ultrawide bandgap semiconductor heterojunction structure. Its advantages include improved stability, photoelectric conversion efficiency, signal-to-noise ratio, and photoresponse current value; at the same time, it reduces costs.
[0006] The above-mentioned utility model objective is achieved through the following technical solution: a deep ultraviolet photodetector with an ultrawide bandgap semiconductor heterojunction structure, comprising a substrate, a DBR layer, a Zn-doped β-Ga2O3 layer, a blocking layer, a Ga-doped γ-GeO2 layer, and a current collection layer; the DBR layer is disposed on the substrate, the Zn-doped β-Ga2O3 layer is disposed on the DBR layer, the blocking layer is disposed on the Zn-doped β-Ga2O3 layer, the Ga-doped γ-GeO2 layer is disposed on the blocking layer, and the current collection layer is disposed on the Ga-doped γ-GeO2 layer; the Zn-doped β-Ga2O3 layer is an N-type semiconductor, the Ga-doped γ-GeO2 layer is a P-type semiconductor, and the Zn-doped β-Ga2O3 layer and the Ga-doped γ-GeO2 layer form a PN heterojunction.
[0007] Preferably, the deep ultraviolet photodetector with an ultrawide bandgap semiconductor heterojunction structure provided by this utility model includes a DBR layer comprising a plurality of first doped semiconductor layers and a plurality of second doped semiconductor layers, wherein the plurality of first doped semiconductor layers and the plurality of second doped semiconductor layers are alternately stacked to form N periodic structures, and the periodic structures form a high reflectivity distributed Bragg mirror, wherein N is a natural number greater than or equal to 10 and less than or equal to 50.
[0008] Preferably, the deep ultraviolet photodetector with an ultrawide bandgap semiconductor heterojunction structure provided by this utility model further includes a top electrode and a bottom electrode, wherein the top electrode is disposed on the current collection layer and the bottom electrode is disposed on the substrate.
[0009] Preferably, in the deep ultraviolet photodetector with an ultrawide bandgap semiconductor heterojunction structure provided by this utility model, the top electrode is made of titanium-gold alloy and the bottom electrode is made of nickel-gold alloy.
[0010] Preferably, in the deep ultraviolet photodetector with an ultrawide bandgap semiconductor heterojunction structure provided by this utility model, the blocking layer is made of Al2O3.
[0011] Preferably, in the deep ultraviolet photodetector with an ultrawide bandgap semiconductor heterojunction structure provided by this utility model, the thickness of the blocking layer ranges from 50 to 100 nm.
[0012] Preferably, in the deep ultraviolet photodetector with an ultrawide bandgap semiconductor heterojunction structure provided by this invention, the current collection layer is made of graphene.
[0013] Preferably, in the deep ultraviolet photodetector with an ultrawide bandgap semiconductor heterojunction structure provided by this utility model, the number of current collection layers ranges from 1 to 5.
[0014] Preferably, in the deep ultraviolet photodetector with an ultrawide bandgap semiconductor heterojunction structure provided by this utility model, the first doped semiconductor layer is Zn-doped β-Ga2O3, and the second doped semiconductor layer is Zn-doped (AlGa)2O3.
[0015] Preferably, in the deep ultraviolet photodetector with an ultrawide bandgap semiconductor heterojunction structure provided by this utility model, the substrate is an N-type silicon substrate.
[0016] In summary, the beneficial technical effects of this utility model are as follows: The deep ultraviolet photodetector with an ultrawide bandgap semiconductor heterojunction structure provided in this application includes a substrate, a DBR layer, a Zn-doped β-Ga2O3 layer, a barrier layer, a Ga-doped γ-GeO2 layer, and a current collection layer; the DBR layer is disposed on the substrate, the Zn-doped β-Ga2O3 layer is disposed on the DBR layer, the barrier layer is disposed on the Zn-doped β-Ga2O3 layer, the Ga-doped γ-GeO2 layer is disposed on the barrier layer, and the current collection layer is disposed on the Ga-doped γ-GeO2 layer; the Zn-doped β-Ga2O3 layer is an N-type semiconductor, the Ga-doped γ-GeO2 layer is a P-type semiconductor, and the Zn-doped β-Ga2O3 layer and the Ga-doped γ-GeO2 layer are... The O2 layer forms a PN heterojunction. By setting a Zn-doped β-Ga2O3 layer and a Ga-doped γ-GeO2 layer, the Zn-doped β-Ga2O3 has a wide bandgap, which can effectively absorb deep ultraviolet light and has good photoelectric conversion efficiency. The large bandgap of β-Ga2O3 helps to enhance the response to the ultraviolet band while suppressing the response to visible light. γ-GeO2 has a wide light absorption range. The combination of the two can improve the sensitivity and photoelectric conversion efficiency of the deep ultraviolet photodetector. In addition, both β-Ga2O3 and γ-GeO2 have high thermochemical stability, which enables the deep ultraviolet photodetector to work stably in high temperature or extreme environments, extending the device life and making it suitable for extreme environments such as aerospace. Attached Figure Description
[0017] Figure 1 This is a cross-sectional view of a deep ultraviolet photodetector with an ultrawide bandgap semiconductor heterojunction structure provided in this embodiment of the present invention.
[0018] Figure 2 This is a schematic diagram of the overall structure of the deep ultraviolet photodetector with an ultrawide bandgap semiconductor heterojunction structure provided in this embodiment of the present invention.
[0019] Figure 3 This is a schematic diagram of the DBR layer in the deep ultraviolet photodetector with an ultrawide bandgap semiconductor heterojunction structure provided in this embodiment of the present invention.
[0020] In the figure, 1 is the deep ultraviolet photodetector; 10 is the substrate; 20 is the DBR layer; 21 is the first doped semiconductor layer; 22 is the second doped semiconductor layer; 30 is the Zn-doped β-Ga2O3 layer; 40 is the barrier layer; 50 is the Ga-doped γ-GeO2 layer; 60 is the current collection layer; 70 is the top electrode; and 80 is the bottom electrode. Detailed Implementation
[0021] The present invention will be further described in detail below with reference to the accompanying drawings.
[0022] Reference Figure 1 and Figure 2 This invention discloses a deep ultraviolet photodetector 1 with an ultrawide bandgap semiconductor heterojunction structure, comprising a substrate 10, a DBR (distributed Bragg reflector) layer 20, a Zn-doped β-Ga₂O₃ (hexagonal gallium oxide) layer 30, a barrier layer 40, a Ga-doped γ-GeO₂ (rutile germanium oxide) layer 50, and a current collection layer 60. The DBR layer 20 is disposed on the substrate 10, the Zn-doped β-Ga₂O₃ layer 30 is disposed on the DBR layer 20, the barrier layer 40 is disposed on the Zn-doped β-Ga₂O₃ layer 30, and the Ga-doped γ-GeO₂ layer 50 is disposed on the barrier layer 60. A barrier layer 40 and a current collection layer 60 are disposed on a Ga-doped γ-GeO2 layer 50; a Zn-doped β-Ga2O3 layer 30 is an N-type semiconductor, and a Ga-doped γ-GeO2 layer 50 is a P-type semiconductor. The Zn-doped β-Ga2O3 layer 30 and the Ga-doped γ-GeO2 layer 50 form a PN heterojunction, which is used for the separation and conduction of photogenerated carriers. By setting up a PN heterojunction, the PN heterojunction can generate photogenerated carriers under ultraviolet light irradiation and effectively separate electrons and holes, improve photoelectric conversion efficiency, effectively reduce dark current, reduce detection noise, and improve signal-to-noise ratio, making it suitable for scenarios requiring high-precision detection.
[0023] By setting a Zn-doped β-Ga2O3 layer and a Ga-doped γ-GeO2 layer 50, the Zn-doped β-Ga2O3 has a wide bandgap, which can effectively absorb deep ultraviolet light and has good photoelectric conversion efficiency. The large bandgap of β-Ga2O3 helps to enhance the response to the ultraviolet band while suppressing the response to visible light. γ-GeO2 has a wide light absorption range. The combination of the two can improve the sensitivity and photoelectric conversion efficiency of the deep ultraviolet photodetector 1. In addition, both β-Ga2O3 and γ-GeO2 have high thermochemical stability, which enables the deep ultraviolet photodetector 1 to work stably in high temperature or extreme environments, extend the device life, and is suitable for extreme environments such as aerospace.
[0024] Specifically, the substrate 10, DBR layer 20, Zn-doped β-Ga2O3 layer 30, barrier layer 40, Ga-doped γ-GeO2 layer 50 and current collection layer 60 are stacked sequentially from bottom to top, wherein the current collection layer 60 is used to collect photocurrent.
[0025] The Zn-doped β-Ga2O3 layer 30, the barrier layer 40, and the Ga-doped γ-GeO2 layer 50 constitute the first heterojunction structure, and the Ga-doped γ-GeO2 layer 50 and the current collection layer 60 constitute the second heterojunction structure. The first heterojunction structure and the second heterojunction structure together form the deep ultraviolet photodetector 1.
[0026] Furthermore, in this embodiment, the barrier layer 40 is made of Al2O3, but this invention is not limited thereto; the thickness of the barrier layer 40 ranges from 50 to 100 nm. The first heterojunction structure combines germanium oxide, aluminum oxide, and gallium oxide, which can provide higher response efficiency and detection sensitivity in the solar blind light band.
[0027] Specifically, a thin layer of alumina is inserted between the Zn-doped β-Ga2O3 layer 30 and the Ga-doped γ-GeO2 layer 50 as a barrier layer 40. This barrier layer 40 has good insulation and high temperature resistance properties, and mainly plays the role of reducing dark current and reducing the recombination rate of dark-state carriers, thereby improving the light-dark current ratio and detection sensitivity of the deep ultraviolet photodetector 1. This barrier layer 40 can not only improve the interface quality of the heterojunction, but also effectively improve the electrical performance of the device.
[0028] Furthermore, the deep ultraviolet photodetector 1 with an ultrawide bandgap semiconductor heterojunction structure provided in this embodiment also includes a top electrode 70 and a bottom electrode 80. The top electrode 70 is disposed on the current collection layer 60, and the bottom electrode 80 is disposed on the substrate 10.
[0029] The top electrode 70 is made of titanium alloy and the bottom electrode 80 is made of nickel alloy, but this utility model is not limited thereto.
[0030] Specifically, the top electrode 70 is composed of a titanium / gold (Ti / Au) alloy with a thickness of 110 nm, providing a low-resistance electrical contact that facilitates current conduction. The combination of titanium and gold offers excellent conductivity and corrosion resistance, making it suitable for high-performance deep ultraviolet photodetectors.
[0031] The bottom electrode 80 is composed of a nickel / gold (Ni / Au) alloy and is used to provide good electrical contact for the substrate 10 and to conduct current. The material selection of the bottom electrode 80 ensures low contact resistance and corrosion resistance.
[0032] Continue to refer to Figures 1 to 3 In this embodiment, the DBR layer 20 includes multiple first doped semiconductor layers 21 and multiple second doped semiconductor layers 22. The multiple first doped semiconductor layers 21 and multiple second doped semiconductor layers 22 are alternately stacked to form N periodic structures. The periodic structures form a high-reflectivity distributed Bragg mirror, where N is a natural number greater than or equal to 10 and less than or equal to 50.
[0033] Specifically, the distributed Bragg reflector can reflect unabsorbed ultraviolet light back to the active layer (i.e., the Zn-doped β-Ga2O3 layer 30 and / or the Ga-doped γ-GeO2 layer 50), enhancing light absorption and improving detection efficiency.
[0034] The first doped semiconductor layer 21 is made of Zn-doped β-Ga2O3, and the second doped semiconductor layer 22 is made of Zn-doped (AlGa)2O3, but this invention is not limited thereto.
[0035] Specifically, the DBR layer 20 consists of N (10 ≤ N ≤ 50) periodic structures of alternating stacked Zn-doped β-Ga2O3 and Zn-doped (AlGa)2O3.
[0036] Continue to refer to Figure 1 and Figure 2 In this embodiment, the current collection layer 60 is made of graphene, but this invention is not limited thereto.
[0037] The number of current collection layers 60 ranges from 1 to 5.
[0038] Specifically, a 1-5 layer graphene current-spreading layer is designed below the top electrode 70 to extend the current laterally, making the current distribution more uniform across the entire surface of the deep ultraviolet photodetector 1. Graphene has high conductivity and transparency, improving conductivity without affecting light transmission.
[0039] Furthermore, in this embodiment, the substrate 10 is an N-type silicon substrate, but the present invention is not limited thereto.
[0040] Specifically, the N-type silicon substrate serves as the supporting structure and provides electrical contacts for the N-type regions. The N-type silicon substrate possesses good mechanical strength and conductivity, which helps reduce manufacturing costs and improve its structural stability.
[0041] The deep ultraviolet photodetector 1 with an ultrawide bandgap semiconductor heterojunction structure provided in this application includes a substrate 10, a DBR layer 20, a Zn-doped β-Ga₂O₃ layer 30, a barrier layer 40, a Ga-doped γ-GeO₂ layer 50, and a current collection layer 60. The DBR layer 20 is disposed on the substrate 10, the Zn-doped β-Ga₂O₃ layer 30 is disposed on the DBR layer 20, the barrier layer 40 is disposed on the Zn-doped β-Ga₂O₃ layer 30, the Ga-doped γ-GeO₂ layer 50 is disposed on the barrier layer 40, and the current collection layer 60 is disposed on the Ga-doped γ-GeO₂ layer 50. The Zn-doped β-Ga₂O₃ layer 30 is an N-type semiconductor, and the Ga-doped γ-GeO₂ layer 50 is a P-type semiconductor. The Zn-doped β-Ga₂O₃ layer 30 and the Ga-doped γ-GeO₂ layer 50 are... A PN heterojunction is formed by a γ-GeO2 doped layer 50. By setting a Zn-doped β-Ga2O3 layer and a Ga-doped γ-GeO2 layer 50, the Zn-doped β-Ga2O3 has a wide bandgap, which can effectively absorb deep ultraviolet light and has good photoelectric conversion efficiency. The large bandgap of β-Ga2O3 helps to enhance the response to the ultraviolet band while suppressing the response to visible light. γ-GeO2 has a wide light absorption range. The combination of the two can improve the sensitivity and photoelectric conversion efficiency of the deep ultraviolet photodetector 1. In addition, both β-Ga2O3 and γ-GeO2 have high thermochemical stability, which enables the deep ultraviolet photodetector 1 to work stably in high temperature or extreme environments, extend the device life, and is suitable for extreme environments such as aerospace.
[0042] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0043] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.
Claims
1. A deep-ultraviolet photodetector of an ultrawide bandgap semiconductor heterojunction structure, characterized in that: The substrate includes a substrate, a DBR layer, a Zn-doped β-Ga2O3 layer, a barrier layer, a Ga-doped γ-GeO2 layer, and a current collecting layer. The DBR layer is disposed on the substrate, the Zn-doped β-Ga2O3 layer is disposed on the DBR layer, the barrier layer is disposed on the Zn-doped β-Ga2O3 layer, the Ga-doped γ-GeO2 layer is disposed on the barrier layer, and the current collecting layer is disposed on the Ga-doped γ-GeO2 layer. The Zn-doped β-Ga2O3 layer is an N-type semiconductor, and the Ga-doped γ-GeO2 layer is a P-type semiconductor, and the Zn-doped β-Ga2O3 layer and the Ga-doped γ-GeO2 layer form a P-N heterojunction.
2. The deep-ultraviolet photodetector of the ultrawide bandgap semiconductor heterojunction structure of claim 1, wherein: The DBR layer includes a plurality of first doped semiconductor layers and a plurality of second doped semiconductor layers, and the plurality of first doped semiconductor layers and the plurality of second doped semiconductor layers are alternately stacked into N periodic structures, and the periodic structure forms a high-reflectivity distributed Bragg reflector, wherein N is a natural number greater than or equal to 10 and less than or equal to 50.
3. The deep-ultraviolet photodetector of the ultrawide bandgap semiconductor heterojunction structure of claim 1, wherein: It also includes a top electrode and a bottom electrode, the top electrode is disposed on the current collecting layer, and the bottom electrode is disposed on the substrate.
4. The deep-ultraviolet photodetector of the ultrawide bandgap semiconductor heterojunction structure of claim 3, wherein: The top electrode is made of titanium gold alloy, and the bottom electrode is made of nickel gold alloy.
5. The deep-ultraviolet photodetector of the ultrawide bandgap semiconductor heterojunction structure of claim 1, wherein: The barrier layer is made of Al2O3.
6. The deep-ultraviolet photodetector of the ultrawide bandgap semiconductor heterojunction structure of claim 5, wherein: The thickness of the barrier layer ranges from 50 to 100 nm.
7. The deep-ultraviolet photodetector of the ultrawide bandgap semiconductor heterojunction structure of claim 1, wherein: The current collecting layer is made of graphene.
8. The deep-ultraviolet photodetector of the ultrawide bandgap semiconductor heterojunction structure of claim 7, wherein: The number of layers of the current collecting layer ranges from 1 to 5 layers.
9. The deep-ultraviolet photodetector of the ultrawide bandgap semiconductor heterojunction structure of claim 2, wherein: The first doped semiconductor layer is made of Zn-doped β-Ga2O3, and the second doped semiconductor layer is made of Zn-doped (AlGa)2O3.
10. The deep-ultraviolet photodetector of the ultrawide bandgap semiconductor heterojunction structure of claim 1, wherein: The substrate is made of an N-type silicon substrate.