Photon energy detector based on double-layer channel p-GaN AlGaN-GaN structure and method

Abstract

The invention discloses a photon energy detector based on a double-layer channel p-GaN AlGaN n-GaN structure and a method, the photon energy detector comprises a first anode, a second anode, a first cathode, a second cathode, a silicon dioxide passivation layer, a p-type GaN layer, a barrier layer, an n-type GaN layer, a GaN buffer layer and an insulating substrate, x represents the molar component of Al in a material, and the value range of x is equal to 0. On the basis of a p-GaN / AlGaN / n-GaN structure, a double-layer channel matched output structure is adopted, and the detector which is high in sensitivity and can detect photon energy is designed.

Description

Technical Field

[0001] This invention relates to the fields of semiconductor device design and photodetection, and particularly to a photon energy detector and method based on a double-channel p-GaNAlGaNn-GaN structure. Background Technology

[0002] GaN devices based on AlGaN / GaN heterojunctions, with their high concentration, high electron mobility, and high electron saturation velocity in a two-dimensional electron gas at the heterojunction, have wide applications in high-frequency, high-speed, and high-power circuits. Among them, enhancement-mode devices based on p-GaN / AlGaN / n-GaN structures have broad application prospects in the field of photodetection. However, conventional p-GaN / AlGaN / n-GaN structures can only obtain information such as output current and gain when performing photodetection, and cannot realize the important function of incident photon energy detection. Summary of the Invention

[0003] The purpose of this invention is to provide a photon energy detector and method based on a dual-channel p-GaN / AlGaN / n-GaN structure to overcome the problems existing in the prior art. Based on the p-GaN / AlGaN / n-GaN structure, this invention adopts a dual-channel output structure to design a highly sensitive detector capable of detecting photon energy.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A photon energy detector based on a dual-channel p-GaNAlGaNn-GaN structure includes a first anode, a second anode, a first cathode, a second cathode, a silicon dioxide passivation layer, and a p-type GaN layer. Barrier layer, n-type GaN layer, GaN buffer layer and insulating substrate, where x represents The molar composition of Al in the material, with x taking values ​​ranging from: ; With the insulating substrate as the bottom, a GaN buffer layer is disposed on the insulating substrate, and a double-layer AlGaN / n-GaN structure is disposed on the GaN buffer layer. The double-layer AlGaN / n-GaN structure consists of a p-type GaN layer, Barrier layer, n-type GaN layer The barrier layer and the n-type GaN layer are stacked sequentially from top to bottom, with the first cathode and the first anode located on the top layer. At the left and right ends of the barrier layer, the second cathode and the second anode are located at the bottom layer, respectively. The silicon dioxide passivation layer fills the bottom layer at both ends of the barrier layer. First cathode, first anode, second cathode, second anode, p-type GaN layer above the barrier layer. The portion outside the barrier layer and the n-type GaN layer.

[0005] Furthermore, the p-type GaN layer is p-type doped with a doping concentration of [value missing]. ; The The barrier layer is undoped; The GaN buffer layer is a transition layer between the insulating substrate and the n-type GaN layer, with a thickness of 0.1 μm to 2 μm; The n-type GaN layer is n-type doped, with a doping concentration of [missing value]. ; The insulating substrate is a high-resistivity substrate with a resistivity of [missing value]. .

[0006] Furthermore, the upper n-type GaN layer and the lower layer The barrier layer, the underlying n-type GaN layer, the GaN buffer layer, and the insulating substrate have equal widths on both sides.

[0007] Furthermore, located in the upper layer The width of the barrier layer is smaller than the width of the upper n-type GaN layer, and the width of the p-type GaN layer is smaller than the width of the upper n-type GaN layer. The width of the barrier layer.

[0008] Furthermore, the first cathode and the first anode are respectively located in the upper layer The left and right ends of the upper surface of the barrier layer are ohmic contact electrodes.

[0009] Furthermore, two grooves are respectively provided at the left and right ends of the upper n-type GaN layer to penetrate the upper n-type GaN layer, and the second cathode and the second anode pass through the left and right grooves respectively and are located in the lower layer. The left and right ends of the upper surface of the barrier layer are ohmic contact electrodes.

[0010] Furthermore, the thickness of the p-type GaN layer is 70 nm. The barrier layer thickness is The thickness of the n-type GaN layer is nm, GaN buffer layer thickness is 10 The thickness of the insulating substrate is .

[0011] Furthermore, the first anode, the second anode, the first cathode, and the second cathode are not connected to each other, and the first anode and the second anode independently output current through two channels.

[0012] Furthermore, the photon energy detector is bilaterally symmetrical.

[0013] The application discloses a detection method of a photonic energy detector based on a double-layer channel p-GaN / AlGaN / n-GaN structure. When the photonic energy detector is used, the first cathode and the second cathode are grounded, unknown light with an intensity of is irradiated from above the p-type GaN layer to the detector surface vertically, the same voltage is connected to the first anode and the second anode, and different currents are outputted on the first anode and the second anode; When no light is added, the p-type GaN layer is depleted of a two-dimensional electron gas channel formed by polarization at the interface of the barrier layer and the n-type GaN layer, the detector is in an off state, a voltage is connected between the first anode and the first cathode, a voltage is connected between the second anode and the second cathode, and no output current is generated on the first anode and the second anode; The absorption coefficient of the n-type GaN layer to the incident light is obtained according to the current difference between the first anode and the second anode, the type of the light is obtained according to the absorption coefficient, and thus photonic energy detection is realized.

[0014] Compared with the prior art, the photonic energy detector based on the double-layer channel p-GaN / AlGaN / n-GaN structure has the following beneficial technical effects: In a conventional p-GaN / AlGaN / n-GaN structure, a high-concentration two-dimensional electron gas is formed at the AlGaN / n-GaN interface due to polarization of the AlGaN and the GaN, the p-GaN layer is depleted of the two-dimensional electron gas of the AlGaN / n-GaN layer below the p-GaN layer, and the device is in an off state. When light is incident on the inner layer from the p-GaN layer, photo-generated carriers and photo-generated electromotive force are generated to make the two-dimensional electron gas channel conduct. In the application, the light is incident on the inner layer of the device from the p-GaN layer, and the two electron gas channels are both conductive. Since the intensity of the light exponentially decays with the depth of the incident light, the currents of the two channels are different. The currents of the two channels are proportional to the intensity of the light, and thus the absorption coefficient of the GaN to the incident light can be obtained according to the difference, the wavelength information of the incident light is obtained, and photonic energy detection is realized. Compared with the conventional p-GaN / AlGaN / n-GaN structure, the photonic energy detector based on the double-layer channel p-GaN / AlGaN / n-GaN structure inherits the high current, high gain and high response speed of the conventional p-GaN / AlGaN / n-GaN structure. According to the current difference of the two conductive channels after light is added, the absorption coefficient of the GaN to the incident light is obtained, the wavelength information of the incident light is obtained, and photonic energy detection is realized. BRIEF DESCRIPTION OF DRAWINGS

[0015] The accompanying drawings are included to provide a further understanding of the application, and are incorporated in and constitute a part of this application. The schematic embodiments of the application and their descriptions serve to explain the application, and do not constitute an improper limitation on the application.

[0016] Figure 1The figure is a schematic diagram of a photonic energy detector based on a double-channel p-GaN / AlGaN / n-GaN structure according to the present application.

[0017] Figure 2 The first channel and the second channel output current-voltage curves after the detector is irradiated by light of two different wavelengths, wherein the first channel current is the first anode output current, the second channel current is the second anode output current, (a) is the first anode output current-voltage curve when the detector is irradiated by light of 365 nm wavelength, (b) is the second anode output current-voltage curve when the detector is irradiated by light of 365 nm wavelength, (c) is the first anode output current-voltage curve when the detector is irradiated by light of 250 nm wavelength, and (d) is the second anode output current-voltage curve when the detector is irradiated by light of 250 nm wavelength. 2 The first channel and the second channel output current-voltage curves after the detector is irradiated by light of two different wavelengths, wherein the first channel current is the first anode output current, the second channel current is the second anode output current, (a) is the first anode output current-voltage curve when the detector is irradiated by light of 365 nm wavelength, (b) is the second anode output current-voltage curve when the detector is irradiated by light of 365 nm wavelength, (c) is the first anode output current-voltage curve when the detector is irradiated by light of 250 nm wavelength, and (d) is the second anode output current-voltage curve when the detector is irradiated by light of 250 nm wavelength. 2 The first channel and the second channel output current-voltage curves after the detector is irradiated by light of two different wavelengths, wherein the first channel current is the first anode output current, the second channel current is the second anode output current, (a) is the first anode output current-voltage curve when the detector is irradiated by light of 365 nm wavelength, (b) is the second anode output current-voltage curve when the detector is irradiated by light of 365 nm wavelength, (c) is the first anode output current-voltage curve when the detector is irradiated by light of 250 nm wavelength, and (d) is the second anode output current-voltage curve when the detector is irradiated by light of 250 nm wavelength.

[0018] Wherein, 1-first anode; 2-second anode; 3-first cathode; 4-second cathode; 5-silicon dioxide passivation layer; 6-p-type GaN layer; 7- Barrier layer; 8-n-type GaN layer; 9-GaN buffer layer; 10-insulating substrate. DETAILED DESCRIPTION

[0019] In order to make the personnel in the art better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0020] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "comprise" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to the process, method, product or device.

[0021] Embodiment one Based on the conventional p-GaN / AlGaN / n-GaN structure, two The barrier layer / n-GaN (i.e. n-type GaN layer) structure forms two conductive channels, and due to the attenuation of incident light in the GaN material, the current of the two conductive channels has a certain difference, and the photon energy of the incident light can be obtained according to the current difference, so that the photon energy detection is realized.

[0022] To realize the above idea, the application provides a photon energy detector based on a double-channel p-GaN / AlGaN / n-GaN structure, which is characterized in that: the photon energy detector comprises a first anode 1, a second anode 2, a first cathode 3, a second cathode 4, a silicon dioxide passivation layer, a p-type GaN layer 6, a barrier layer 7, an n-type GaN layer 8, a GaN buffer layer 9, and an insulating substrate 10.

[0023] The bottom of the application is the insulating substrate 10, and the GaN buffer layer 9 is arranged on the insulating substrate 10, and the two together form a substrate layer. The double-channel p-GaN / AlGaN / n-GaN structure is formed on the substrate layer, and the double-channel p-GaN / AlGaN / n-GaN structure is composed of the p-type GaN layer 6, the barrier layer 7, and the n-type GaN layer 8, which are stacked from bottom to top in sequence.

[0024] Further, the thickness of the p-type GaN layer 6 is 70 nm, the thickness of the n-type GaN layer 8 is nm, the thickness of the barrier layer 7 is , and the thickness of the GaN buffer layer 9 is 10 , and the thickness of the insulating substrate 10 is .

[0025] Further, the n-type GaN layer 8 on the upper layer, the n-type GaN layer 8 on the lower layer, and the barrier layer 7 on the lower layer have the same width as the insulating substrate 10 and the GaN buffer layer 9, and the width of the barrier layer 7 on the upper layer is smaller than the width of the n-type GaN layer 8 on the lower layer. The width of the p-type GaN layer 6 is smaller than the width of the barrier layer 7 on the upper layer. The entire double-channel p-GaN / AlGaN / n-GaN structure is left-right symmetrical.

[0026] Further, the p-type GaN layer 6 is p-type doped, and the doping concentration is ; the barrier layer 7 and the GaN buffer layer 9 are not doped; the GaN buffer layer 9 is a transition layer between the insulating substrate 10 and the n-type GaN layer 8, and the thickness is 0.1 μm ~ 2 μm; the n-type GaN layer 8 is n-type doped, and the doping concentration is ; and the insulating substrate 10 is a high-resistance substrate, and the resistivity is​ .

[0027] Further, The Al component x in the barrier layer 7 is .

[0028] Further, a recess is etched on each of the left and right ends of the upper n-type GaN layer 8, and the recesses on the left and right ends pass through the n-type GaN layer 8.

[0029] Further, the first cathode 3 and the first anode 1 are arranged on the left and right ends of the upper surface of the barrier layer 7; the second cathode 4 and the second anode 2 respectively pass through the recesses and are in contact with the upper surface of the lower barrier layer 7. Further, the four electrodes (the first anode 1, the second anode 2, the first cathode 3, and the second cathode 4) are ohmic contact electrodes.

[0030] Further, a silicon dioxide passivation layer 5 is generated on the upper surface of the lower barrier layer 7, and the silicon dioxide passivation layer 5 fills the portions outside the p-type GaN layer 6, the n-type GaN layer 8, and the barrier layer 7.

[0031] Further, in use, a certain light with an intensity of is vertically irradiated from above the detector to the surface of the p-type GaN layer 6, the first cathode 3 and the second cathode 4 are grounded, the first anode 1 and the second anode 2 are connected to a certain voltage, and the first anode 1 and the second anode 2 both have output currents.

[0032] A photonic energy detector based on a double-layer channel p-GaN / AlGaN / n-GaN structure has the following basic detection principles and processes: Due to the piezoelectric polarization and spontaneous polarization of the barrier layer 7 and the spontaneous polarization of the n-type GaN layer 8, a high-concentration two-dimensional electron gas is formed at the / n-GaN interface. In the detector, the heavily doped p-type GaN layer 6 depletes the two-dimensional electron gas in the two channels below the p-type GaN layer 6, and the device is in an off state without light. In use: 1) A certain light with a certain intensity is vertically irradiated from above the detector to the surface of the p-type GaN layer 6, the n-type GaN layer 8 absorbs the light to generate photo-generated carriers, the two conductive channels are reformed, the first cathode 3 and the second cathode 4 are grounded, the first anode 1 and the second anode 2 are connected to a certain voltage, and the first anode 1 and the second anode 2 both have output currents. 2) Since the intensity of the light in the n-type GaN layer 8 exponentially decays with the depth of incidence, the light intensity at the depth of incidence y is

[0033] , where ​​​​The initial light intensity, Let be the absorption coefficient of GaN for this light. Output current of the first anode 1. For the upper level Barrier layer / n-GaN interface (depth) Two-dimensional electron gas channel current, second anode 2 output current For the lower level Barrier layer / n-GaN interface (depth) Two-dimensional electron gas channel current, due to the difference in light absorption intensity at the two interfaces and , The ratio is the ratio of light intensities, therefore / , That is, the thickness d of the upper n-type GaN layer 8, can be obtained .

[0034] The light absorption coefficient of GaN material is obtained based on the above process. This allows us to obtain the wavelength information of the incident light, and thus achieve photon energy detection.

[0035] Example 2 A photon energy detector based on a dual-channel p-GaN / AlGaN / n-GaN structure, such as Figure 1 As shown: The detector is constructed based on a conventional p-GaN / AlGaN / n-GaN structure, using an insulating substrate 10 and a GaN buffer layer 9 as substrates. A double-channel p-GaN / AlGaN / n-GaN structure is formed on the substrate, consisting of a p-type GaN layer 6, ... Barrier layer 7, n-type GaN layer 8, The barrier layer 7 and the n-type GaN layer 8 are stacked sequentially from top to bottom. The first cathode 3 and the first anode 1 are located on the upper layer. At the left and right ends of the barrier layer 7, the second cathode 4 and the second anode 2 are located in the lower layer, respectively. The left and right ends of the barrier layer 7, and the second cathode 4 and the second anode 2 are respectively inserted into the left and right grooves of the upper n-type GaN layer 8, thus connecting with the lower layer. Barrier layer 7 is in contact. Silicon dioxide passivation layer 5 is located in the lower layer. The layer above the barrier layer 7 is filled with p-type GaN layer 6. The portion excluding the barrier layer 7, the n-type GaN layer 8, and the electrodes (including the first cathode 3, the first anode 1, the second cathode 4, and the second anode 2).

[0036] The present invention is implemented as follows: In this embodiment, the doping concentration of the p-type GaN layer 6 is [value missing]. ; Barrier layer 7 and GaN buffer layer 9 are undoped; n-type GaN layer 8 is n-type doped with a doping concentration of [missing value]. .

[0037] In this embodiment, the p-type GaN layer 6 has a thickness of 70 nm and a width of 6 mm on each side. ; The barrier layer 7 is 10 nm thick, and the n-type GaN layer 8 is 20 nm thick; the upper layer The barrier layer 7 has a width of 10. The width of the upper n-type GaN layer 8 and all layers below it is 14. The width of the grooves on both sides of the upper n-type GaN layer is 1. The distance between the left edge of the left groove and the left edge of the entire device is 1. The distance between the right edge of the right groove and the right edge of the entire device is 1. The entire detector is symmetrical from left to right. In this embodiment, all electrodes are ohmic contact electrodes.

[0038] In this embodiment, The Al component x in barrier layer 7 is .

[0039] Figure 1 This image shows a detailed cross-section of the detector, which is 100 mm wide perpendicular to this section. .

[0040] The simulation of the basic working process of a photon energy detector based on a dual-channel p-GaN / AlGaN / n-GaN structure is as follows: The p-type GaN layer 6 will exhaust the resources below it. The two-dimensional electron gas at the interface of barrier layer 7 / n-type GaN layer 8 indicates that all conductive channels are in an off state. In use: 1) The first cathode 3 and the second cathode 4 are grounded, and their respective strengths are set to... Two wavelengths of light are emitted perpendicularly downwards from above the p-type GaN layer 6, onto the upper surface of the detector. Both n-type GaN layers 8 absorb the light, generating electron-hole pairs. These electron-hole pairs narrow the space charge region of the n-type GaN layer 8, thus affecting the two detector layers. A conductive channel is formed at the interface between barrier layer 7 and n-type GaN layer 8. By applying a 5 V voltage to the first anode 1 and the second anode 2, an output current can be generated on the n-type GaN layer 8. The simulation results are as follows. Figure 2 As shown.

[0041] 2) Figure 2The middle (a) is the response current after the first incident light is incident, and the first anode 1 plus 5 V can obtain the first anode 1 output current (the first channel current) , the second anode 2 plus 5 V voltage can obtain the second anode 2 output current (the second channel current) , according to / d is the distance of the first channel and the second channel, in the embodiment, the first channel is the two-dimensional electron gas channel of the interface between the upper layer barrier layer 7 / n-type GaN layer 8, and the second channel is the two-dimensional electron gas channel of the interface between the lower layer barrier layer 7 / n-type GaN layer 8, so that d is 20 nm in the embodiment, and then 1.02359 can be calculated, by referring to the absorption coefficient of GaN to different light, it can be obtained that the incident light wavelength is 365 nm, and the photon energy is 3.4 eV. Figure 2 The middle (b) is the response current after the second incident light is incident, and the first anode 1 plus 5 V can obtain the first channel current , the second anode 2 plus 5 V voltage can obtain the second channel current , according to / , 1.94969 can be obtained, by referring to the absorption coefficient of GaN to different light, it can be obtained that the incident light wavelength is 250 nm, and the photon energy is 4.9 eV. From the above results, it can be known that the detector can obtain the incident light wavelength and the photon energy according to the difference between the two channel currents, and then realize the photon energy detection.

[0042] The GaN light absorption coefficient is obtained through the above process, so that the type of incident light is obtained, and the photon energy detection is realized.

[0043] In summary, the application uses the double-layer channel p-GaN / AlGaN / n-GaN structure based on the conventional p-GaN / AlGaN / n-GaN structure, and realizes the photon energy detection according to the difference between the two channel currents on the basis of inheriting the high gain and high response speed of the conventional p-GaN / AlGaN / n-GaN structure, so that the application range and function of the device in the light detection field are improved.

[0044] ​​It should be pointed out finally that the above embodiments are only used for illustrating the technical solutions of the present application but not for limiting the protection scope thereof, and although the present application has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the specific embodiments of the present application can be changed, modified or replaced equivalently by those skilled in the art after reading the present application, but these changes, modifications or equivalent replacements are all within the protection scope of the claims of the present application to be approved.

Claims

1. A photonic energy detector based on a double channel p-GaN / AlGaN / n-GaN structure, characterized in that, It includes a first anode (1), a second anode (2), a first cathode (3), a second cathode (4), a silicon dioxide passivation layer (5), and a p-type GaN layer (6). The structure consists of a barrier layer (7), an n-type GaN layer (8), a GaN buffer layer (9), and an insulating substrate (10), where x represents... The molar composition of Al in the material, with x taking values ​​ranging from: ; The insulating substrate (10) is taken as the bottom, a GaN buffer layer (9) is arranged on the insulating substrate (10), a double-layer AlGaN / n-GaN structure is arranged on the GaN buffer layer (9), the double-layer AlGaN / n-GaN structure is composed of a p-type GaN layer (6), a barrier layer (7), an n-type GaN layer (8), The barrier layer (7) and the n-type GaN layer (8) are sequentially stacked from top to bottom, the first cathode (3) and the first anode (1) are respectively located at the left and right ends of the uppermost layer of the barrier layer (7), the second cathode (4) and the second anode (2) are respectively located at the left and right ends of the lowermost layer of the barrier layer (7), and the silicon dioxide passivation layer (5) is filled in the lowermost layer of the barrier layer (7). The first cathode (3), the first anode (1), the second cathode (4), the second anode (2), the p-type GaN layer (6), and the n-type GaN layer (8) are all arranged above the barrier layer (7).

2. The dual layer channel p-GaN AlGaN n-GaN structure photonic energy detector according to claim 1, wherein, The p-type GaN layer (6) is p-type doped with a doping concentration of ; The The barrier layer (7) is not doped; The GaN buffer layer (9) is a transition layer between the insulating substrate (10) and the n-type GaN layer (8), and the thickness is 0.1-2 microns; The n-type GaN layer (8) is n-type doped with a doping concentration of ; The insulating substrate (10) is a high resistance substrate, with an electrical resistivity of .

3. The dual layer channel p-GaN AlGaN n-GaN structure photonic energy detector according to claim 1, wherein, The n-type GaN layer (8) on the upper layer, the n-type GaN layer (8) on the lower layer The barrier layer (7), the n-type GaN layer (8) on the lower layer, and the GaN buffer layer (9), and the insulating substrate (10) have the same width.

4. The dual layer channel p-GaN AlGaN n-GaN structure photonic energy detector according to claim 3, wherein, The upper layer The width of the barrier layer (7) is smaller than the width of the upper n-type GaN layer (8), and the width of the p-type GaN layer (6) is smaller than the width of the upper The width of the barrier layer (7).

5. The dual layer channel p-GaN AlGaN n-GaN structure photonic energy detector according to claim 1, wherein, The first cathode (3) and the first anode (1) are respectively located at the upper layer of The upper surface of the barrier layer (7) is provided with ohmic contact electrodes at the left and right ends.

6. The dual layer channel p-GaN AlGaN n-GaN structure photonic energy detector according to claim 5, wherein, Two recesses are arranged at the left and right ends of the upper n-type GaN layer (8) and pass through the upper n-type GaN layer (8), the second cathode (4) and the second anode (2) pass through the left and right recesses respectively and are located at the lower layer The upper surface of the barrier layer (7) is provided with ohmic contact electrodes at the left and right ends.

7. The dual layer channel p-GaN AlGaN n-GaN structure photonic energy detector according to claim 1, wherein, The thickness of the p-type GaN layer (6) is 70 nm, The thickness of the barrier layer (7) is The thickness of the n-type GaN layer (8) is nm, and the thickness of the GaN buffer layer (9) is 10 The thickness of the insulating substrate (10) is .

8. The dual layer channel p-GaN AlGaN n-GaN structure photonic energy detector according to claim 1, wherein, The first anode (1), the second anode (2), the first cathode (3) and the second cathode (4) are not connected with each other, and the first anode (1) and the second anode (2) independently output the current of two channels.

9. The dual layer channel p-GaN AlGaN n-GaN structure photonic energy detector according to claim 1, wherein, The photon energy detector is left-right symmetrical.

10. The method of a photonic energy detector based on a double-layered channel p-GaN AlGaN n-GaN structure according to any one of claims 1-9, characterized in that, In use, the first cathode (3) and the second cathode (4) are grounded, and light of an unknown type with an intensity of is irradiated vertically from above the p-type GaN layer (6) and downwards onto the surface of the detector, the same voltage is applied to the first anode (1) and the second anode (2), and different magnitudes of current are output from the first anode (1) and the second anode (2). The p-type GaN layer (6) is depleted without light The two-dimensional electron gas channel formed by polarization at the interface between the barrier layer (7) and the n-type GaN layer (8), the detector is in the off state, a voltage is applied between the first anode (1) and the first cathode (3), a voltage is applied between the second anode (2) and the second cathode (4), and no output current is generated at the first anode (1) and the second anode (2); The absorption coefficient of the n-type GaN layer (8) to incident light is obtained according to the current difference of the first anode (1) and the second anode (2), the type of light is obtained according to the absorption coefficient, and thus the photon energy is detected.

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