GaN-based self-driven narrow-band photoelectric detector with double-gate control structure, and preparation method and application of GaN-based self-driven narrow-band photoelectric detector

Abstract

The invention discloses a GaN-based self-driven narrow-band photoelectric detector with a double-gate control structure and a preparation method and application of the GaN-based self-driven narrow-band photoelectric detector, and belongs to the technical field of semiconductor photoelectric detectors. The preparation method comprises the following steps: sequentially epitaxially growing a buffer layer, a first absorption layer, an insertion layer, a second absorption layer and a polarization layer on the surface of a substrate; etching along one side of the polarization layer until a part of the second absorption layer is exposed, and reserving a part of the polarization layer on the second absorption layer; etching the middle part of the second absorption layer which is not covered by the polarization layer, and etching a groove in the middle of the second absorption layer; preparing a metal thin layer in the groove; preparing a Bragg reflector above the metal thin layer; and preparing a first metal electrode above the polarization layer, and preparing a second metal electrode above the second absorption layer. According to the photoelectric detector, low-noise self-driven operation is achieved, and the light-dark suppression ratio and the response sensitivity can be effectively improved while narrow-band detection is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor optoelectronic devices, and more specifically, to a GaN-based self-driven narrowband photodetector with a dual-gate control structure, a preparation method thereof, and applications thereof. Background Art

[0002] A photodetector is a device that converts light signals into electrical signals. That is, photons are incident on the photodetector to generate electron-hole pairs, and then an external bias is applied to allow the photogenerated electrons and holes to be transported inside the device to form a photocurrent, thus achieving light-to-electrical signal conversion. Photodetectors can be used in optical communications, optical imaging, flame detection, biomedical testing and other fields according to their different detection bands.

[0003] In order to meet the needs of different market applications, various types of photodetectors have been developed, including metal-semiconductor-metal (MSM) photodetectors, PIN junction photodetectors, avalanche photodetectors (APDs), surface plasmon polaritons (SPR) photodetectors, etc. Among them, MSM photodetectors have attracted widespread attention due to their advantages such as fast response speed, high sensitivity and simple production.

[0004] The traditional symmetrical MSM photodetector includes a substrate, a buffer layer, an absorption layer, and a metal electrode in sequence along the epitaxial growth direction. The main shortcomings of this structure are that the luminescence band detected by the absorption layer is relatively wide, the device has a large dark current, and is unable to detect small signals. Therefore, it cannot be applied to high-confidential optical communications, fluorescence detection, artificial vision and other fields.

[0005] The prior art discloses a self-powered MSM type ZnO-based ultraviolet photodetector, which is used to solve the problems of low responsivity of the MSM type ultraviolet detector, need for an external power supply, and failure to meet the bandpass response.

[0006] However, the above-mentioned photodetectors still have certain deficiencies in terms of responsiveness and narrow-band detection, and further optimization is urgently needed. Summary of the invention

[0007] The technical problem to be solved by the present invention is to overcome the shortcomings of existing metal-semiconductor-metal (MSM) photodetectors, such as wide luminous band, high dark current and low responsivity of the devices, and to provide a method for preparing a GaN-based self-driven narrow-band photodetector with a dual-gate control structure. The prepared photodetector can realize wavelength detection in a specific narrow band range, and can increase photocurrent, reduce dark current, and has a higher responsivity.

[0008] Another object of the present invention is to provide a GaN-based self-driven narrow-band photodetector with a dual-gate control structure.

[0009] Another object of the present invention is to provide an application of a GaN-based self-driven narrow-band photodetector with a dual-gate control structure.

[0010] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0011] A method for preparing a GaN-based self-driven narrow-band photodetector with a dual-gate control structure comprises the following steps:

[0012] S1. epitaxially growing a buffer layer, a first absorption layer, an insertion layer, a second absorption layer and a polarization layer on the substrate surface in sequence;

[0013] S2. Etching along one side of the polarization layer to expose a portion of the second absorption layer, and retaining a portion of the polarization layer on the second absorption layer;

[0014] S3. Etching the middle portion of the second absorption layer not covered by the polarization layer, and etching a groove in the middle of the second absorption layer;

[0015] S4. Preparing a metal thin layer in the groove;

[0016] S5. Preparing a Bragg reflector above the metal thin layer;

[0017] S6. Prepare a first metal electrode above the polarization layer, and prepare a second metal electrode above the second absorption layer.

[0018] The present invention utilizes GaN and its ternary compound material system as an absorption layer, and forms a double-gate control structure of a metal gate and a polarization gate formed by a metal thin layer / a second absorption layer / an insertion layer, thereby forming a negatively polarized charge and a gold semi-contact depletion region, regulating the depletion effect of electrons in the absorption layer (regulating the distribution of the depletion electric field), regulating the carrier transport channel, and having a good "pinch-off" effect on the two-dimensional electron gas channel, effectively reducing the dark current of the device under no light conditions, and regulating the transport behavior of background carriers and photogenerated carriers in the detector, thereby significantly improving the photocurrent and responsiveness; and improving the detection rate of the device.

[0019] The light absorption region of the detector of the present invention is also provided with a distributed Bragg reflector (DBR) and a planar metal thin layer structure. When a light wave is incident on the DBR / metal structure, the energy of the light wave can be converted into Tamm plasmons, thereby forming a standing wave at the interface. This standing wave has a very narrow bandwidth and can produce a significant field enhancement effect at the interface, thereby realizing the detection of wavelengths in a specific narrow band range, solving the limitation that traditional detectors cannot select a specific band for detection. Thus, the response speed and sensitivity of the self-driven narrowband detector are improved.

[0020] The present invention etches along one side of the polarization layer through step S2, retains part of the polarization layer on the second absorption layer to form an asymmetric polarization layer structure, and utilizes the polarization electric field generated by the asymmetric polarization layer structure to regulate the separation and transmission of photogenerated carriers in the absorption layer, thereby realizing low-noise self-driven operation without external voltage conditions.

[0021] In summary, the present invention realizes low-noise self-driven operation, which can effectively improve the light-dark suppression ratio and response sensitivity while realizing narrow-band detection.

[0022] In a specific embodiment, the substrate can be ultrasonically treated with acetone, alcohol, and deionized water, and blown dry with nitrogen.

[0023] In a specific embodiment, in step S1, a buffer layer, a first absorption layer, an insertion layer, a second absorption layer and a polarization layer can be epitaxially grown in sequence on the surface of the substrate by thin film epitaxial growth technology such as deposition, evaporation or sputtering to obtain the basic epitaxial layer structure of the detector.

[0024] In a specific implementation, in step S2, photolithography and dry etching processes can be used to etch along one side of the polarization layer to expose a portion of the second absorption layer, etch out a device table exposing a portion of the second absorption layer, and etch the polarization layer to leave the polarization layer on a portion of the upper surface of the table to produce a locally distributed polarization layer structure.

[0025] In a specific implementation, in step S3, the middle of the second absorption layer can be etched by photolithography and dry etching processes to etch a groove in the middle of the second absorption layer.

[0026] In a specific implementation, in step S4, a thin metal layer may be evaporated in the groove by using a thin film epitaxial growth technique such as deposition, evaporation or sputtering.

[0027] In a specific implementation, in step S5, a Bragg reflector (DBR) covered on the metal thin layer can be manufactured by thin film epitaxial growth technology of deposition, evaporation or sputtering, as well as photolithography and lift-off technology.

[0028] In a specific implementation, in step S6, the first metal electrode and the second metal electrode may be manufactured using photolithography technology and metal evaporation technology.

[0029] Preferably, the material of the first absorption layer is In x1 Ga 1-x1 N or Al x2 Ga 1-x2 N, each component coefficient is 0≤x1<1, 0≤x2<1; the thickness of the first absorption layer is 0.1μm to 1μm;

[0030] The material of the second absorption layer is In x1 Ga 1-x1 N or Al x2 Ga 1-x2 N, each component coefficient is 0≤x1≤1, 0≤x2≤1; the thickness of the second absorption layer is 0.9μm~4μm.

[0031] Preferably, the material of the insertion layer is In y1 Ga 1-y1 N or Al y2 Ga 1-y2 N, the coefficients of each component are 0≤y1≤1, 0≤y2≤1, y1<x1,y2> x2, the thickness of the insertion layer is 1nm to 50nm.

[0032] Preferably, the material of the polarization layer is In z1 Ga 1-z1 N or Al z2 Ga 1-z2 N, the coefficients of each component are 0≤z1≤1, 0≤z2≤1, z1<x1,z2> x2, the thickness of the polarization layer is 5nm to 100nm.

[0033] Preferably, the material of the metal thin layer is Ti, Au, Ag, Al or Ni, and the thickness of the metal thin layer is 1 nm to 120 nm.

[0034] Preferably, the material of the DBR is SiO2 / MoS2, Al2O3 / TiO2 or SiO2 / TiO2. The number of periods and the thickness of each layer need to be determined according to the central absorption wavelength of the DBR.

[0035] Preferably, the projection area of ​​the groove is 10% to 70% of the surface area of ​​the second absorption layer, and the depth of the groove is less than the thickness of the second absorption layer.

[0036] Preferably, the material of the first metal electrode and the second metal electrode is Ti / Au, Ni / Au, Cr / Au, Ti / Al / Ni / Au or Ti / Al / Ti / Au, and the thickness of the first metal electrode is 10nm~800nm; the thickness of the second metal electrode is 10nm~800nm.

[0037] In a specific embodiment, the substrate is made of sapphire, SiC, Si, GaN or AlN;

[0038] In a specific implementation, the buffer layer is made of GaN or AlN and has a thickness of 1 μm to 3 μm.

[0039] The present invention also protects the GaN-based self-driven narrow-band photodetector with a dual-gate control structure prepared by the method for preparing the GaN-based self-driven narrow-band photodetector with a dual-gate control structure described in any one of the above items.

[0040] The present invention also protects the application of the above-mentioned GaN-based self-driven narrow-band photodetector with a dual-gate control structure in optical communication, fluorescence detection, artificial vision, optical imaging, flame detection, and biomedical detection.

[0041] Because optical communications, especially high-confidential optical communications, use specific narrow bands to reduce interference and crosstalk, improve signal selectivity and security, enhance anti-interference capabilities, and meet the needs of customized services and regulatory standards, thereby ensuring the clarity, reliability, and confidentiality of communications. Therefore, it is particularly important to detect wavelengths in a specific narrow band range. For fluorescence detection, flame detection, and biomedical detection, specific narrow bands can improve selectivity, reduce background interference, and enhance the signal-to-noise ratio, thereby improving the sensitivity and accuracy of detection. For artificial vision and optical imaging, specific narrow bands can improve the recognition accuracy of specific targets or features, reduce environmental interference, and enhance image contrast and resolution, thereby achieving more accurate and reliable visual perception in complex environments.

[0042] The operating process of the GaN-based self-driven narrow-band photodetector with a dual-gate control structure and the preparation method thereof in the present invention is possessed by technicians in this technical field. The raw materials involved can be obtained through general channels. The process is simple and reliable, has strong repeatability, and has low production cost. It is suitable for industrial promotion and can be applied to the field of narrow-band photoelectric detection.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The present invention discloses a GaN-based self-driven narrow-band photodetector with a dual-gate control structure and a preparation method thereof. The GaN-based self-driven narrow-band photodetector with a dual-gate control structure is prepared, which uses GaN and its ternary compound material system as an absorption layer, has a metal gate and a polarization gate formed by a metal thin layer / a second absorption layer / an insertion layer, a distributed Bragg reflector (DBR), and an asymmetric polarization layer structure.

[0045] The photoelectric detector of the present invention realizes low-noise self-driven operation, and can effectively improve the light-dark suppression ratio and response sensitivity while realizing narrow-band detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 Schematic diagram of the structure of the GaN-based self-driven narrow-band photodetector with a dual-gate control structure of Example 1.

[0047] Figure 2 This is a schematic diagram of the structure of a standard MSM type ultraviolet detector in the prior art of comparative example 1.

[0048] Figure 3 It is a comparison diagram of the photocurrent and dark current of Example 1 and Comparative Example 1.

[0049] Figure 4 It is a comparison diagram of the responsiveness of Example 1 and Comparative Example 1.

[0050] Among them, 101. substrate, 102. buffer layer, 1031. first absorption layer, 104. insertion layer, 1032. second absorption layer, 105. metal thin layer, 106. polarization layer, 107. first metal electrode, 108. second metal electrode, 109. Bragg reflector. DETAILED DESCRIPTION

[0051] The present invention is further described below in conjunction with specific embodiments, but the embodiments do not limit the present invention in any form. Unless otherwise specified, the raw materials and reagents used in the embodiments of the present invention are conventionally purchased raw materials and reagents.

[0052] The preparation methods involved include photolithography, etching, metal evaporation, etc., which are all common operating processes, and the raw materials involved can be obtained through general channels.

[0053] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0054] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0055] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0056] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0057] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0058] Example 1

[0059] like Figure 1 As shown, a GaN-based self-driven narrow-band photodetector with a dual-gate control structure, the preparation method includes the following steps:

[0060] S1. In an MOCVD reactor, epitaxially grow a buffer layer 102 on the surface of the substrate 101 at a growth temperature of 1050° C. and a gas pressure of 50 mbar, thereby filtering dislocation defects and releasing stress caused by lattice mismatch; continue to epitaxially grow a first absorption layer 1031, an insertion layer 104, a second absorption layer 1032 and a polarization layer 106 at a growth temperature of 1050° C. and a gas pressure of 50 mbar;

[0061] S2. Etching along the right side of the polarization layer 106 by photolithography and dry etching process to expose part of the second absorption layer 1032, and retaining the left part of the polarization layer 106 on the second absorption layer 1032;

[0062] S3. Etching the middle portion of the second absorption layer 1032 not covered by the polarization layer 106 by photolithography and dry etching processes, and etching a groove in the middle of the second absorption layer 1032;

[0063] S4. Using the e-beam evaporation process to first evaporate the metal thin layer 105 in the groove;

[0064] S5. In a PECVD reactor, a DBR layer 109 is alternately epitaxially grown on the surface of the metal thin layer 105 at a growth temperature of 200°C / 180°C and a pressure of 120Pa / 60Pa. The DBR 109 is etched by photolithography and etching processes so that the DBR 109 remains only above the metal thin layer 105.

[0065] S6. Using photolithography technology and e-beam evaporation process, a first metal electrode 107 is prepared on the polarization layer 106, and a second metal electrode 108 is prepared on the second absorption layer 1032 on the right side of the groove.

[0066] The substrate 101 is made of sapphire.

[0067] The buffer layer 102 is made of AlN and has a thickness of 2 μm.

[0068] The material of the first absorption layer 1031 is Al x2 Ga 1-x2 N, x2=0, i.e. GaN; the thickness of the first absorption layer 1031 is 3 μm;

[0069] The material of the second absorption layer 1032 is Al x2 Ga 1-x2 N, x2=0, ie, GaN; the thickness of the second absorption layer 1032 is 1 μm.

[0070] The projection area of ​​the groove is 40% of the surface area of ​​the second absorption layer 1032 , and the depth of the groove is 0.8 um, which is less than the thickness of the second absorption layer 1032 .

[0071] The material of the insertion layer 104 is Al y2 Ga 1-y2 N, the coefficient of each component is y2 = 0.2, that is, Al 0.2 Ga 0.8 N, the thickness of the insertion layer 104 is 20 nm.

[0072] The material of the metal thin layer 105 is Au, and the thickness of the metal thin layer 105 is 20 nm.

[0073] The material of the polarization layer 106 is Al z2 Ga 1-z2 N, the coefficient of each component is z2 = 0.2, that is, Al0.2 Ga 0.8 N, the thickness of the polarization layer 106 is 100 nm.

[0074] The first metal electrode 107 and the second metal electrode 108 are made of Ni / Au. The thickness of the first metal electrode 107 is 100 nm; the thickness of the second metal electrode 108 is 100 nm.

[0075] The material of DBR109 is SiO2 / MoS2, Al2O3 / TiO2 or SiO2 / TiO2. The material of DBR109 is 8 pairs of Al2O3 / TiO2, wherein the thickness of each pair of Al2O3 / TiO2 is 30nm and 22nm respectively.

[0076] Example 2

[0077] A GaN-based self-driven narrowband photodetector with a dual-gate control structure is different from Example 1 in that the material and period of DBR 109 are composed of 5 pairs of SiO2 / TiO2, and the thicknesses thereof are 35nm and 22nm respectively.

[0078] Example 3

[0079] A GaN-based self-driven narrow-band photodetector with a dual-gate control structure is different from Example 1 in that: the metal thin layer 105 is made of Ag and has a thickness of 100 nm.

[0080] Example 4

[0081] A GaN-based self-driven narrowband photodetector with a dual-gate control structure is different from Example 1 in that:

[0082] The buffer layer 102 is made of AlN and has a thickness of 1 μm.

[0083] The material of the first absorption layer 1031 is Al x2 Ga 1-x2 N, x2=0, i.e. GaN; the thickness of the first absorption layer 1031 is 3 μm;

[0084] The material of the second absorption layer 1032 is Al x2 Ga 1-x2 N, x2=0, ie, GaN; the thickness of the second absorption layer 1032 is 1 μm.

[0085] The projection area of ​​the groove is 40% of the surface area of ​​the second absorption layer 1032 , and the depth of the groove is 0.5 um, which is smaller than the thickness of the second absorption layer 1032 .

[0086] The material of the insertion layer 104 is Al y2 Ga 1-y2N, the coefficient of each component is y2 = 0.2, that is, Al 0.2 Ga 0.8 N, the thickness of the insertion layer 104 is 1 nm.

[0087] The material of the metal thin layer 105 is Au, and the thickness of the metal thin layer 105 is 10 nm.

[0088] The material of the polarization layer 106 is Al z2 Ga 1-z2 N, the coefficient of each component is z2 = 0.2, that is, Al 0.2 Ga 0.8 N, the thickness of the polarization layer 106 is 5 nm.

[0089] The first metal electrode 107 and the second metal electrode 108 are made of Ni / Au. The thickness of the first metal electrode 107 is 10 nm; the thickness of the second metal electrode 108 is 10 nm.

[0090] The material of DBR109 is 8 pairs of Al2O3 / TiO2, wherein the thickness of each pair of Al2O3 / TiO2 is 30nm and 22nm respectively.

[0091] Example 5

[0092] A GaN-based self-driven narrowband photodetector with a dual-gate control structure is different from Example 1 in that:

[0093] The buffer layer 102 is made of AlN and has a thickness of 3 μm.

[0094] The material of the first absorption layer 1031 is Al x2 Ga 1-x2 N, x2=0, i.e. GaN; the thickness of the first absorption layer 1031 is 4 μm;

[0095] The material of the second absorption layer 1032 is Al x2 Ga 1-x2 N, x2=0, ie, GaN; the thickness of the second absorption layer 1032 is 1 μm.

[0096] The projection area of ​​the groove is 40% of the surface area of ​​the second absorption layer 1032 , and the depth of the groove is 0.8 um, which is less than the thickness of the second absorption layer 1032 .

[0097] The material of the insertion layer 104 is Al y2 Ga 1-y2 N, the coefficient of each component is y2 = 0.2, that is, Al 0.2 Ga 0.8 N, the thickness of the insertion layer 104 is 50 nm.

[0098] The material of the metal thin layer 105 is Au, and the thickness of the metal thin layer 105 is 120 nm.

[0099] The material of the polarization layer 106 is Al z2 Ga 1-z2 N, the coefficient of each component is z2 = 0.2, that is, Al 0.2 Ga 0.8 N, the thickness of the polarization layer 106 is 100 nm.

[0100] The first metal electrode 107 and the second metal electrode 108 are made of Ni / Au. The thickness of the first metal electrode 107 is 800 nm; the thickness of the second metal electrode 108 is 800 nm.

[0101] The material of DBR109 is 8 pairs of Al2O3 / TiO2, wherein the thickness of each pair of Al2O3 / TiO2 is 30nm and 22nm respectively.

[0102] Comparative Example 1

[0103] like Figure 2 As shown, an MSM type ultraviolet detector comprises, from bottom to top, a substrate 101 , a buffer layer 102 , an absorption layer 103 , a metal electrode 107 and a metal electrode 108 , wherein the metal electrode 107 and the metal electrode 108 are respectively located on the surface of the absorption layer 103 .

[0104] The materials of each layer are the same as those in Example 1 and will not be described again here.

[0105] Results

[0106] The standard MSM type ultraviolet detectors of the above embodiments and comparative examples were tested for relevant performances:

[0107] (1) Photocurrent and dark current: In the voltage range of -10V to +10V, the test method is TCAD simulation. The unit is A / m.

[0108] The specific test results of Example 1 and Comparative Example 1 are shown in Tables 1 and Figure 3 As shown:

[0109] Table 1

[0110]

[0111] (2) Response sensitivity: The test method is TCAD simulation software. The unit is A / W.

[0112] The specific test results of Example 1 and Comparative Example 1 are shown in Tables 2 and Figure 4 As shown:

[0113] Table 2

[0114]

[0115]

[0116] It can be seen from the above results that compared with comparative example 1, due to the polarization gate, metal gate and DBR structure, the detector of the embodiment of the present invention realizes the detection of wavelengths in a specific narrow band range of 200 to 360 nm. Compared with the standard MSM ultraviolet detector, the dark current of the GaN-based self-driven narrowband photodetector with a dual-gate control structure represented by the dotted line is significantly reduced, indicating that under no light conditions, the dual-gate control structure has a good "pinch-off" effect on the two-dimensional electron gas channel. At the same time, the photocurrent of the GaN-based self-driven narrowband photodetector with a dual-gate control structure is also significantly higher than that of the standard MSM ultraviolet detector. Therefore, the light-dark suppression ratio of the GaN-based self-driven narrowband photodetector with a dual-gate control structure is greatly improved. The dark current of embodiment 1 is more than four orders of magnitude lower than that of comparative example 1, which is sufficient to show that the noise is low; and the asymmetric photocurrent under forward and reverse bias can well reflect the self-driving performance of the device. The design of the present invention improves the responsiveness and sensitivity of the detector, while realizing low-noise self-driven operation, overcoming the limitations of traditional detectors in narrow-band photodetection.

[0117] In Example 2, by accurately matching the period and material of the metal thin layer 105 and the DBR 109, high-intensity absorption of different narrow-band luminescence bands can be achieved based on the influence of the DBR reflector and optical transmission, and the combined influence of the strong absorption of the band by Tamm plasmons at the metal and semiconductor interface.

[0118] The narrow-band photodetectors in the above-mentioned embodiments can all be realized and have a certain influence on the detector light and dark current. In addition, the effect of the narrow-band photodetector will be affected by the material, size and component changes of the first absorption layer, the second absorption layer, the insertion layer, the metal thin layer, the DBR layer and the polarization layer in the detector. Therefore, it is necessary to make appropriate optimization according to different device structures and process methods to make the narrow-band photodetector achieve the best effect.

[0119] Matters not covered by the present invention are known technologies.

[0120] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for preparing a GaN-based self-driven narrow-band photodetector with a dual-gate control structure, characterized in that: The steps include: S1. epitaxially growing a buffer layer (102), a first absorption layer (1031), an insertion layer (104), a second absorption layer (1032) and a polarization layer (106) in sequence on the surface of the substrate (101); S2. Etching along one side of the polarization layer (106) until a portion of the second absorption layer (1032) is exposed, and a portion of the polarization layer (106) is retained on the second absorption layer (1032); S3. etching the middle portion of the second absorption layer (1032) not covered by the polarization layer (106), and etching a groove in the middle portion of the second absorption layer (1032); S4. Preparing a metal thin layer (105) in the groove; S5. Preparing a Bragg reflector (109) above the metal thin layer (105); S6. Prepare a first metal electrode (107) above the polarization layer (106), and prepare a second metal electrode (108) above the second absorption layer (1032).

2. The method for preparing a GaN-based self-driven narrow-band photodetector with a dual-gate control structure according to claim 1, characterized in that: The material of the first absorption layer (1031) is In x1 Ga 1-x1 N or Al x2 Ga 1-x2 N, each component coefficient is 0≤x1<1, 0≤x2<1; the thickness of the first absorption layer (1031) is 0.9μm to 4μm; The material of the second absorption layer (1032) is In x1 Ga 1-x1 N or Al x2 Ga 1-x2 N, the coefficients of each component are 0≤x1<1, 0≤x2<1; and the thickness of the second absorption layer (1032) is 0.1 μm to 1 μm.

3. The method for preparing a GaN-based self-driven narrow-band photodetector with a dual-gate control structure as claimed in claim 2, characterized in that: The material of the insertion layer (104) is In y1 Ga 1-y1 N or Al y2 Ga 1-y2 N, the coefficients of each component are 0≤y1≤1, 0≤y2≤1, y1<x1,y2> x2, the insertion layer (104) has a thickness of 1 nm to 50 nm.

4. The method for preparing a GaN-based self-driven narrow-band photodetector with a dual-gate control structure as claimed in claim 2, characterized in that: The material of the polarization layer (106) is In z1 Ga 1-z1 N or Al z2 Ga 1-z2 N, the coefficients of each component are 0≤z1≤1, 0≤z2≤1, z1<x1,z2> x2, the thickness of the polarization layer (106) is 5nm to 100nm.

5. The method for preparing the GaN-based self-driven narrow-band photodetector with a dual-gate control structure as claimed in claim 1, characterized in that: The material of the metal thin layer (105) is Ti, Au, Ag, Al or Ni, and the thickness of the metal thin layer (105) is 1 nm to 120 nm.

6. The method for preparing a GaN-based self-driven narrow-band photodetector with a dual-gate control structure according to claim 1, characterized in that: The material of the DBR (109) is SiO2 / MoS2, Al2O3 / TiO2 or SiO2 / TiO2.

7. The method for preparing a GaN-based self-driven narrow-band photodetector with a dual-gate control structure according to claim 1, characterized in that: The projection area of ​​the groove is 10% to 70% of the surface area of ​​the second absorption layer (1032), and the depth of the groove is less than the thickness of the second absorption layer (1032).

8. The method for preparing a GaN-based self-driven narrow-band photodetector with a dual-gate control structure according to claim 1, characterized in that: The materials of the first metal electrode (107) and the second metal electrode (108) are Ti / Au, Ni / Au, Cr / Au, Ti / Al / Ni / Au or Ti / Al / Ti / Au, the thickness of the first metal electrode (107) is 10nm to 800nm; the thickness of the second metal electrode (108) is 10nm to 800nm.

9. A GaN-based self-driven narrow-band photodetector with a dual-gate control structure prepared by the method for preparing a GaN-based self-driven narrow-band photodetector with a dual-gate control structure according to any one of claims 1 to 8.

10. Application of the GaN-based self-driven narrow-band photodetector with a dual-gate control structure as claimed in claim 9 in optical communication, fluorescence detection, artificial vision, optical imaging, flame detection, and biomedical detection.

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