Multi-mode reconfigurable diamond solar-blind ultraviolet photoelectric transistor and preparation method thereof

Abstract

The invention discloses a multi-mode reconfigurable diamond solar-blind ultraviolet photoelectric transistor and a preparation method thereof, and aims to solve the problem of separation of sensing, storage and calculation frameworks of an existing artificial vision system. According to the diamond solar blind ultraviolet photoelectric transistor, a terminal is arranged on the surface of a diamond substrate, a first metal film layer is deposited on the upper surface of the diamond substrate to serve as a first contact electrode, the first contact electrode is Schottky contact, and a second contact electrode is a metal probe. The second contact electrode is in needle point contact with the upper surface of the diamond substrate, a second metal film layer is deposited on the lower surface of the diamond substrate to serve as a third contact electrode, and the third contact electrode is Schottky contact. According to the reconfigurable diamond solar blind ultraviolet photoelectric transistor, different functions of an avalanche detector, an optical memory, visual synapse and the like are integrated in one device, and large gain rising of the diamond detector and multi-mode intelligent sensing of a single device are achieved.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor electronic devices, and in particular relates to a multi-modal reconfigurable diamond solar-blind ultraviolet phototransistor and a preparation method thereof. Background Art

[0002] Thanks to their lack of natural background noise and the absence of complex filtering, solar-blind UV detection technology based on wide-bandgap semiconductors holds an irreplaceable position in applications such as aircraft plume monitoring, corona detection, and non-line-of-sight UV communications. Diamond, a representative third-generation semiconductor material, boasts excellent comprehensive properties, making it a leading choice for solar-blind UV detection. However, due to limitations in crystal quality, high ohmic contact interface resistance, and difficulty in n-type doping, traditional diamond photodetectors based on photoconductivity are limited by intrinsic absorptivity, photoelectric conversion efficiency, and a lack of internal gain mechanisms. Their responsivity is limited to the mA / W level (Liu B, Liu K, Zhang S, et al. Self-powered solar-blind UV detectors based on O-terminated vertical diamond Schottky diode with low dark current, high detectivity, and high signal-to-noise ratio [J]. ACS Applied Electronic Materials), and their external quantum efficiency cannot exceed 100%. This extremely weak photoelectric response makes it impractical, making it incapable of detecting weak solar-blind UV signals that are severely attenuated in air. Ge Lei and his colleagues at Shandong University have developed a series of hydrogen-terminated diamond-based phototransistors ("Preparation and Performance of Hydrogen-Terminated Diamond Field-Effect Transistors and UV Detectors"), which exhibit high responsivity (R) and specific detectivity (D*). However, the hydrogen-terminated surface is susceptible to oxidation and thermal desorption, and the metal electrode has poor adhesion to it, resulting in insufficient device stability and reliability, making it difficult to operate in extreme environments.

[0003] With breakthroughs in artificial intelligence (AI) big models, the emergence of embodied AI, and the advent of the Internet of Things (IoT), sensor technology is evolving from single-mode light intensity detection to neuromorphic devices that integrate multimodal fusion and high-dimensional perception. Neuromorphic devices mimic the dynamic characteristics of biological neurons and synapses, deeply integrating sensing, storage, and computing functions. This achieves integrated sensing, storage, and computing, significantly improving energy efficiency and parallel processing capabilities compared to traditional von Neumann architectures. Photoelectric memristors, a typical example of neuromorphic devices, exhibit multiple photo-switchable resistance states under light irradiation, combining light sensing and memory functions. They can be used to develop rewritable non-volatile memories and hardware neural networks, making them crucial for the realization of next-generation neuromorphic computing. However, due to structural and performance differences, the photodetector used for solar-blind ultraviolet sensing and the memristor units used for storage and computing are typically physically separated, increasing size, complexity, and energy consumption. This has hindered the development of integrated AI vision systems for the solar-blind ultraviolet band. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem of separation of sensing, storage and computing architectures in existing solar-blind ultraviolet photoelectric devices and to provide a multi-modal reconfigurable diamond solar-blind ultraviolet phototransistor.

[0005] The multimodal reconfigurable diamond solar-blind ultraviolet phototransistor of the present invention includes a diamond substrate, a first contact electrode, a second contact electrode and a third contact electrode. The (upper and lower) surfaces of the diamond substrate are provided with terminals. A first metal film layer is deposited on the upper surface (one side) of the diamond substrate as the first contact electrode, and the first contact electrode is a Schottky contact. The second contact electrode is a metal probe, and the second contact electrode contacts the needle tip of the upper surface of the diamond substrate. A second metal film layer is deposited on the lower surface of the diamond substrate as the third contact electrode, and the third contact electrode is a Schottky contact.

[0006] The preparation method of the multi-modal reconfigurable diamond solar-blind ultraviolet phototransistor of the present invention is achieved by the following steps:

[0007] 1. First, immerse the diamond substrate in aqua regia and boil it, then ultrasonically clean it to obtain a cleaned diamond substrate;

[0008] 2. Performing surface termination treatment on the cleaned diamond substrate using a wet chemical method or a plasma method to obtain a diamond substrate with a terminal;

[0009] 3. Depositing a first metal film layer as a first contact electrode on the upper surface of the diamond substrate with the terminal, and depositing a second metal film layer as a third contact electrode on the lower surface of the diamond substrate with the terminal, to obtain a diamond substrate with a Schottky contact drain and gate;

[0010] 4. A second contact electrode is set on the upper surface of the diamond substrate with Schottky contact drain and gate. The second contact electrode is a metal probe. The second contact electrode is set apart from the first contact electrode to obtain a multimodal reconfigurable diamond solar-blind ultraviolet phototransistor.

[0011] This invention provides a multimodal, reconfigurable diamond solar-blind ultraviolet phototransistor that integrates diverse functions, including an avalanche detector, a photomemristor, and a visual synapse, into a single device. The device utilizes a transition metal and surface terminations to create a Schottky-contact drain and gate, forming a metal-semiconductor contact field-effect transistor (MESFET) structure. This structure exhibits extremely high adhesion and an ultra-high built-in electric field. The source electrode utilizes a needle-tip contact structure. Due to the surface termination, in the absence of light, the source needle-tip forms a high-barrier Schottky contact with the diamond surface, forming a barrier-symmetrical MSM structure with the drain Schottky contact. This structure maintains an ultra-low dark current of picoamps within a ±200 V test bias range. Because the needle tip has an extremely small contact area, the photogenerated electric field under illumination cancels out the Schottky chip's built-in electric field, significantly reducing the Schottky barrier at the source tip contact. This results in a low load voltage divider in the circuit loop, thus forming an intrinsic diamond Schottky photodiode in contact with the drain Schottky chip. The ultra-high electric field strength in the junction region accelerates avalanche multiplication of photogenerated carriers, achieving a high signal-to-noise ratio (SNR) of "dark current avalanche-free photocurrent avalanche." Multimodal reconfigurability utilizes the Schottky gate electric field to control carrier transport in the channel. Compared to conventional two-terminal photoelectric devices, the gate-assisted diamond phototransistor of this invention achieves extremely high photoresponse and gain, enabling avalanche detection in day-blind ultraviolet light under Geiger mode. It also exhibits excellent self-powered detection properties under 0 V drain and gate bias. Simultaneously, the light-gating effects of the surface terminal and gate enable the device to exhibit the neuromorphic characteristics of multi-bit optical storage of photomemristors and light-enhanced short-term plasticity of visual synapses.

[0012] The multimodal reconfigurable diamond solar-blind ultraviolet phototransistor of the present invention has a simple structure and integrates different functions such as an avalanche detector, a photomemristor, and a visual synapse in a single device, achieving a significant leap in the gain of traditional diamond detectors and multimodal intelligent perception of a single device. It solves the problems of low responsiveness of current diamond solar-blind ultraviolet photodetectors, poor stability of hydrogen-terminated diamond phototransistors, and only being able to achieve a single light intensity detection function. Compared with ultraviolet photomultiplier tubes and silicon-based ultraviolet avalanche detectors that also have high gain, the present invention has the advantages of no need for filters, no need for auxiliary heat dissipation, and small volume load assembly; compared with ordinary diamond photodetectors, it has lower noise and higher responsiveness in photoelectric detection performance, and functionally integrates multimodal reconfigurable characteristics such as avalanche detectors, photomemristors, and visual synapses. It can provide solutions for different types of applications such as weak solar-blind signal detection and sensing in different environments such as on the ground and in space, meet the urgent needs for aircraft tail flame detection, high-voltage leakage corona inspection, and ultraviolet light communication, and is expected to achieve the integration of "detection-identification-decision-making" and promote the construction of the next generation of solar-blind ultraviolet multimodal intelligent perception system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the structure of the multi-modal reconfigurable diamond solar-blind ultraviolet phototransistor of the present invention, wherein 1 is a diamond substrate, 2 is a terminal, 3 is a first contact electrode, 4 is a second contact electrode, and 5 is a third contact electrode;

[0014] Figure 2 This is a simulation diagram of the electric field intensity distribution of the multi-modal reconfigurable diamond solar-blind ultraviolet phototransistor in the embodiment when light is present, the drain and gate are biased at -200 V, and the source is grounded;

[0015] Figure 3 : This is the output characteristic curve of the measured photoelectric response test of the multi-modal reconfigurable diamond solar-blind ultraviolet phototransistor in the embodiment;

[0016] Figure 4 The measured photoelectric response test transfer characteristic curve of the multi-modal reconfigurable diamond solar-blind ultraviolet phototransistor in the embodiment;

[0017] Figure 5 2 is a current-time response curve of the multi-modal reconfigurable diamond solar-blind ultraviolet phototransistor in an embodiment;

[0018] Figure 6 : is a simulation diagram of the electric field intensity of the multi-modal reconfigurable diamond solar-blind ultraviolet phototransistor under a bias voltage of 0 V in the embodiment;

[0019] Figure 7 In the embodiment, the multi-mode reconfigurable diamond solar-blind ultraviolet phototransistor is G=0V shows the characteristic diagram of the "pinch hysteresis loop" of the photoelectric memristor;

[0020] Figure 8 is the gate voltage V of the multi-modal reconfigurable diamond solar-blind UV phototransistor under cyclic bias in the embodiment G =-100V shows the characteristic diagram of the "pinch hysteresis loop" of the photoelectric memristor;

[0021] Figure 9 2 is a characteristic diagram of light-enhanced synaptic plasticity exhibited by the multimodal reconfigurable diamond solar-blind ultraviolet phototransistor in the embodiment under stimulation of a 220 nm light pulse. DETAILED DESCRIPTION

[0022] Specific embodiment 1: In this embodiment, the multimodal reconfigurable diamond day-blind ultraviolet phototransistor includes a diamond substrate 1, a first contact electrode 3, a second contact electrode 4 and a third contact electrode 5. The (upper and lower) surfaces of the diamond substrate 1 are provided with terminals 2. A first metal film layer is deposited on the upper surface (one side) of the diamond substrate 1 as the first contact electrode 3. The first contact electrode 3 is a Schottky contact. The second contact electrode 4 is a metal probe. The second contact electrode 4 is in needle-tip contact with the upper surface of the diamond substrate 1. A second metal film layer is deposited on the lower surface of the diamond substrate 1 as the third contact electrode 5. The third contact electrode 5 is a Schottky contact.

[0023] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that the diamond substrate is electronic grade diamond, the nitrogen impurity content in the diamond substrate is less than 5 ppb, and the boron impurity content is less than 1 ppb.

[0024] Specific embodiment three: This embodiment is different from specific embodiment one or two in that the terminal 2 on the diamond substrate 1 is a hydrogen terminal, an oxygen terminal, a nitrogen terminal or a fluorine terminal.

[0025] Specific embodiment 4: This embodiment differs from specific embodiments 1 to 3 in that the thickness of the first contact electrode 3 is 0.1-10 μm, and the thickness of the third contact electrode 5 is 0.1-10 μm.

[0026] Specific embodiment five: The difference between this embodiment and any one of specific embodiments one to four is that the material of the first metal film layer is a laminated material of one or more metals selected from Pt, Cr, Ru, W, Ti, Zr, and Au; the material of the second metal film layer is a laminated material of one or more metals selected from Pt, Cr, Ru, W, Ti, Zr, and Au.

[0027] Specific embodiment 6: This embodiment differs from specific embodiments 1 to 5 in that the material of the metal probe is W, Pt or Au, and the radius of the needle tip is 0.01-2 μm.

[0028] Specific embodiment seven: The preparation method of the multi-modal reconfigurable diamond solar-blind ultraviolet phototransistor of this embodiment is implemented according to the following steps:

[0029] 1. First, immerse the diamond substrate 1 in aqua regia and boil it, and then ultrasonically clean it to obtain a cleaned diamond substrate;

[0030] 2. Performing surface termination treatment on the cleaned diamond substrate using a wet chemical method or a plasma method to obtain a diamond substrate with a terminal;

[0031] 3. Depositing a first metal film layer as a first contact electrode 3 on the upper surface of the diamond substrate with the terminal, and depositing a second metal film layer as a third contact electrode 5 on the lower surface of the diamond substrate with the terminal, thereby obtaining a diamond substrate with Schottky contact drain and gate;

[0032] 4. A second contact electrode 4 is set on the upper surface of the diamond substrate with Schottky contact drain and gate. The second contact electrode 4 is a metal probe. The second contact electrode 4 is set apart from the first contact electrode 3, thereby obtaining a multimodal reconfigurable diamond solar-blind ultraviolet phototransistor with both avalanche detection function and neuromorphic characteristics.

[0033] In this embodiment, when the diamond substrate has a hydrogen terminal, the first metal film layer is composed of one or more metal films such as Al or Ti having a work function lower than 4.5 eV.

[0034] Specific embodiment eight: This embodiment differs from specific embodiment seven in that in step one, the diamond substrate 1 is ultrasonically cleaned using deionized water, anhydrous ethanol, and acetone in sequence.

[0035] Specific embodiment nine: This embodiment differs from specific embodiments seven or eight in that the wet chemical method described in step two is to place the cleaned diamond substrate in a mixed oxidizing strong acid and boil it at 350°C for 1 to 3 hours. The mixed oxidizing strong acid is a mixture of H2SO4 with a mass concentration of 98% and HNO3 with a mass concentration of 68% in a volume ratio of 3:1.

[0036] Specific embodiment ten: The difference between this embodiment and any one of specific embodiments seven to nine is that the plasma method described in step two is to place the cleaned diamond substrate in an excited gas plasma environment for surface treatment, and the excited gas is hydrogen, nitrogen, fluorine-containing electronic special gas (CF4 or XeF2) or oxygen.

[0037] Example: The method for preparing a multi-modal reconfigurable diamond solar-blind ultraviolet phototransistor with both avalanche detection function and neuromorphic characteristics in this embodiment is implemented according to the following steps:

[0038] First, immerse the electronic grade diamond substrate 1 in aqua regia and boil it, then ultrasonically clean it to obtain a cleaned diamond substrate;

[0039] Second, the cleaned diamond substrate was boiled in a mixture of 98% H2SO4 and 68% HNO3 at a volume ratio of 3:1 at 350°C for 2 hours to perform surface termination treatment, obtaining a diamond substrate with oxygen terminations.

[0040] 3. On the upper surface of the diamond substrate with oxygen termination, 30 nm of Pt and 70 nm of Au were sequentially deposited as the first contact electrode 3. On the lower surface of the diamond substrate with oxygen termination, 30 nm of Pt and 70 nm of Au were sequentially deposited as the third contact electrode 5 to obtain a diamond substrate with Schottky contact drain and gate electrodes.

[0041] 4. A second contact electrode 4 is set on the upper surface of the diamond substrate with Schottky contact drain and gate. The second contact electrode 4 is a metal W probe. The second contact electrode 4 is spaced apart from the first contact electrode 3 to obtain a multimodal reconfigurable diamond solar-blind ultraviolet phototransistor.

[0042] In this embodiment, the first contact electrode 3 serves as the drain of the transistor, the second contact electrode 4 serves as the source, and the third contact electrode 5 serves as the gate.

[0043] The multimodal reconfigurable diamond solar-blind ultraviolet phototransistor of this embodiment has a surface terminal prepared on the surface of an electronic-grade diamond with extremely high crystal quality, and a high-barrier Schottky contact drain, a gate, and a needle-tip contact source with adjustable photoinduced barrier are respectively prepared on the surface terminal, thereby integrating multimodal reconfigurable features such as an avalanche detector, an optical memory, and a visual synapse in one device.

[0044] After TCAD simulation ( Figure 2 ), at drain bias V D = -200 V, gate bias V G = -200 V, under the condition of UV light and the source of the needle tip is grounded, the Schottky junction region can generate a maximum of 2.743 × 10 7The electric field of 10 V / cm has exceeded the breakdown field strength limit of diamond (about 10 MV / cm) [ Wort CJH, Balmer R S. Diamond as anelectronic material[J]. Materials today, 2008, 11(1-2): 22-28.], [ Balmer RS,Brandon JR, Clewes SL, et al. Chemical vapor deposition synthetic diamond:materials, technology and applications[J]. Journal of Physics: CondensedMatter, 2009, 21(36): 364221.].

[0045] Photoelectric test data (attached Figure 3 Output characteristic curve and attached Figure 4 The transfer characteristic curve shows that the detector (with an effective area of ​​1.77 × 10 -4 cm 2 ) In the absence of light, the dark current can be lower than 0.1 nA within the gate voltage range of ±200 V without avalanche breakdown; under 220 nm ultraviolet light (power density of 4.23×10 -6 W / cm 2 ) irradiated, the photogenerated carriers generate avalanche multiplication under the acceleration of the Schottky built-in electric field, which stimulates a large number of electrons. The avalanche photocurrent is generated at the Schottky gate (V G ) further amplified, a large photoelectric response is generated. G As the voltage increases, the threshold turn-on voltage increases significantly, which is manifested as a positive shift in the IV characteristic curve. This is due to the light gating effect of the Schottky gate. After calculation, the extreme responsivity R=9.97 ×10 6 A / W, external quantum efficiency EQE=5.62×10 9 %, specific detection degree D*=3.99×10 19 Jones (drain bias V D = +200 V, V G = -200 V), far exceeding the performance of all currently published diamond detectors.

[0046] The multi-modal reconfigurable characteristics of the multi-modal reconfigurable diamond solar-blind ultraviolet phototransistor of this embodiment are achieved by adjusting V G Implementation. D = -200 V, V G= -200 V, the Schottky junction field strength has exceeded the diamond limit breakdown field strength. At this time, the diamond phototransistor can operate in the Geiger mode of avalanche detection. After the avalanche current is generated, even if the light source is turned off, the current only changes slightly and cannot immediately return to the dark current level. It may even not respond to the on / off of the incident light signal. After the ultraviolet light is turned off, the device continues to maintain an ultra-high avalanche current (see attached figure). Figure 5 ), which can be used for extremely weak or even single-photon avalanche detection.

[0047] In V G With V D When both are 0 V, the diamond phototransistor of the present invention has good self-powered working characteristics, with a power of 6.6×10 5 The ultra-high light-dark current suppression ratio of the level is still as high as 2.0×10 5 V / cm (with Figure 6 ), there may be impact ionization of carriers. D With V G The self-powered diamond phototransistor has an R of 6.5 A / W and a D* of 1.8×10- 15 Jones.

[0048] The multimodal reconfigurable diamond solar-blind UV phototransistor of this embodiment can also demonstrate the multi-bit optical storage of photomemristors and the light-enhanced short-term plasticity neuromorphic characteristics of visual synapses. For example, under 220 nm ultraviolet irradiation, the V G =0 V (with Figure 7 ), when a reverse bias is applied to the device from the initial state of 0 V, avalanche multiplication will not occur, and it will show a high resistance state (HRS). However, at a threshold voltage of around -200 V, the device photocurrent will undergo a Set operation due to the ultra-high electric field strength to produce avalanche multiplication, entering a low resistance state (LRS) with a large current. A huge avalanche photocurrent will be generated in the range from -200 V to 0 V, and a positive bias can reset the device in the avalanche multiplication mode to the HRS state. This resistive switching behavior related to the applied voltage polarity is a characteristic of a bipolar memristor. The resistive switching characteristics of the device are significantly related to the incident light and the electrode size. An increase in the incident light power and the increase in the device area will cause the HRS resistance to decrease, so that the light wavelength information can be stored in a non-volatile manner as a multi-level resistor without affecting the LRS of the device. Therefore, the incident light wavelength can be used to realize multi-bit storage programming of the device. The resistive switching characteristics of the device are similar to those at V G =-100 V (with Figure 8), the device turn-on voltage will shift from 0 V to about -100 V, where the device is in the reverse biased cutoff state from 0 to -100 V, and in the forward conduction state from -100 to -200 V. When the bias is swept from -200 V to 0 V, no avalanche multiplication occurs, which manifests as HRS, but when it is swept from 0 V to -200 V, the device turns on the avalanche multiplication mode and enters LRS. The device also exhibits the neural characteristics of visual synapses. When the device is irradiated with 220 nm pulsed ultraviolet light, the device will cause a persistent photoconductivity tail due to the light gating effect. The excitatory postsynaptic current generated by the second pulse stimulation is stronger than the first stimulation response. Multiple superpositions will cause a significant increase in the photocurrent, which manifests as a double-pulse facilitation phenomenon of the visual synapse (see Appendix). Figure 9 ), which is an important function reflecting the phenomenon of synaptic short-term plasticity.

[0049] In summary, the multimodal reconfigurable diamond solar-blind ultraviolet phototransistor of the present invention has a simple structure, achieves a significant leap in the gain of the diamond detector and single-device multimodal intelligent perception, and solves the problems of low response of the current diamond solar-blind ultraviolet photodetector, poor stability of the hydrogen-terminated diamond phototransistor, and only being able to realize a single light intensity detection function. It is expected to realize the integration of "detection-identification-decision-making" in application scenarios such as tail flame detection, and promote the construction of the next generation of solar-blind ultraviolet multimodal intelligent perception systems.

Claims

1. Multimodal reconfigurable diamond solar-blind ultraviolet phototransistor, characterized by The multimodal reconfigurable diamond solar-blind ultraviolet phototransistor comprises a diamond substrate (1), a first contact electrode (3), a second contact electrode (4) and a third contact electrode (5), wherein the surface of the diamond substrate (1) is provided with a terminal (2), a first metal film layer is deposited on the upper surface of the diamond substrate (1) as the first contact electrode (3), the first contact electrode (3) is a Schottky contact, the second contact electrode (4) is a metal probe, the second contact electrode (4) is in needle-tip contact with the upper surface of the diamond substrate (1), and a second metal film layer is deposited on the lower surface of the diamond substrate (1) as the third contact electrode (5), the third contact electrode (5) is a Schottky contact.

2. The multimodal reconfigurable diamond solar-blind ultraviolet phototransistor according to claim 1, characterized in that The diamond substrate is electronic grade diamond, the nitrogen impurity content in the diamond substrate is less than 5 ppb, and the boron impurity content is less than 1 ppb.

3. The multimodal reconfigurable diamond solar-blind ultraviolet phototransistor according to claim 1, characterized in that The terminal (2) on the diamond substrate (1) is a hydrogen terminal, an oxygen terminal, a nitrogen terminal or a fluorine terminal.

4. The multimodal reconfigurable diamond solar-blind ultraviolet phototransistor according to claim 1, characterized in that The thickness of the first contact electrode (3) is 0.1-10 μm, and the thickness of the third contact electrode (5) is 0.1-10 μm.

5. The multimodal reconfigurable diamond solar-blind ultraviolet phototransistor according to claim 1, characterized in that The material of the first metal film layer is a laminated material of one or more metals among Pt, Cr, Ru, W, Ti, Zr, and Au; the material of the second metal film layer is a laminated material of one or more metals among Pt, Cr, Ru, W, Ti, Zr, and Au.

6. The multi-modal reconfigurable diamond solar-blind ultraviolet phototransistor according to claim 1, characterized in that The material of the metal probe is W, Pt or Au, and the radius of the tip is 0.01~2 μm.

7. The method for preparing the multimodal reconfigurable diamond solar-blind ultraviolet phototransistor according to claim 1, characterized in that The preparation method is achieved by the following steps:

1. First, immerse the diamond substrate (1) in aqua regia and boil it, and then ultrasonically clean it to obtain a cleaned diamond substrate; 2. Performing surface termination treatment on the cleaned diamond substrate using a wet chemical method or a plasma method to obtain a diamond substrate with a terminal; 3. depositing a first metal film layer as a first contact electrode (3) on the upper surface of the diamond substrate with the terminal, and depositing a second metal film layer as a third contact electrode (5) on the lower surface of the diamond substrate with the terminal, thereby obtaining a diamond substrate with a Schottky contact drain and a gate; 4. A second contact electrode (4) is provided on the upper surface of the diamond substrate with the Schottky contact drain and gate, the second contact electrode (4) being a metal probe, and the second contact electrode (4) is spaced apart from the first contact electrode (3), thereby obtaining a multi-modal reconfigurable diamond solar-blind ultraviolet phototransistor.

8. The method for preparing a multi-modal reconfigurable diamond solar-blind ultraviolet phototransistor according to claim 7, characterized in that In step 1, the diamond substrate (1) is ultrasonically cleaned using deionized water, anhydrous ethanol, and acetone in sequence.

9. The method for preparing a multi-modal reconfigurable diamond solar-blind ultraviolet phototransistor according to claim 7, characterized in that The wet chemical method described in step 2 is to place the cleaned diamond substrate in a mixed oxidizing strong acid and boil it at 350°C for 1 to 3 hours. The mixed oxidizing strong acid is a mixture of 98% H2SO4 and 68% HNO3 in a volume ratio of 3:

1.

10. The method for preparing a multi-modal reconfigurable diamond solar-blind ultraviolet phototransistor according to claim 7, characterized in that The plasma method in step 2 is to place the cleaned diamond substrate in an exciting gas plasma environment for surface treatment, and the exciting gas is hydrogen, nitrogen, fluorine-containing electronic special gas or oxygen.

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