Dual-mode optoelectronic device integrating optical synapse and photodetection function and preparation method thereof

Abstract

This invention discloses a dual-mode optoelectronic device integrating photosynaptic and photodetector functions and its fabrication method, belonging to the field of optoelectronic technology. It includes an n-type GaN nanowire structure disposed on a substrate; a CsPbBr3 quantum dot layer disposed on the surface of the n-type GaN nanowire structure, forming a CsPbBr3 / GaN heterojunction; and an electrode lead-out terminal electrically connected to the CsPbBr3 / GaN heterojunction. The CsPbBr3 quantum dot layer disposed on the surface of the n-type GaN nanowire structure, combined with the CsPbBr3 quantum dot layer, constitutes the working electrode of the CsPbBr3 / GaN heterojunction. In closed-loop mode, the CsPbBr3 quantum dot layer, as an excellent light absorption and carrier generation layer, combined with the built-in electric field at the heterojunction interface, greatly improves the separation and transport efficiency of photogenerated carriers. Compared with a bare GaN control device, the device of this invention has a significantly higher photoresponse current, stronger photoresponse output capability, and significantly improved photodetector performance.

Description

Technical Field

[0001] This invention belongs to the field of optoelectronic device technology, specifically relating to a dual-mode optoelectronic device integrating photosynaptic and photodetector functions and its fabrication method. Background Technology

[0002] With the development of neuromorphic computing and artificial vision systems, optosynaptic devices have demonstrated significant application value in simulating biological visual perception and information processing due to their ability to directly convert optical signals into synaptic-like electrical responses. An ideal optosynaptic device not only needs high sensitivity to optical signals but also the ability to controllably remember and weight optical stimuli to achieve integrated perception and processing. However, existing optosynaptic devices generally face the problem of a single optical response mode in practical applications. Most devices are designed with an emphasis on synaptic memory characteristics, and their working mechanism relies on carrier trapping, interface state accumulation, or ion migration processes to maintain a certain electrical response after the removal of optical stimulation. While this mechanism is beneficial for achieving synaptic plasticity, it usually results in a slow optical response speed, making it difficult to effectively sense transient or high-frequency optical signals, thus limiting its application in real-time optical sensing systems. In contrast, traditional photodetectors are characterized by high-speed separation and transport of photogenerated carriers, enabling rapid response to optical signals. However, their output signals decay rapidly after the optical stimulus disappears, lacking the ability to remember and accumulate optical information, making it difficult to meet the demands of synaptic behavior in neuromorphic computing. Therefore, devices operating in a single mode cannot simultaneously satisfy both optical sensing and optical memory requirements.

[0003] For the reasons mentioned above, there is an urgent need for a simple, tunable photosynaptic device that can exhibit different photoresponse characteristics under different operating states, thus achieving both rapid photoelectric response and synaptic memory-like behavior in the same device. In particular, how to achieve switching between different photoresponse modes through reasonable device structure design and electrical control methods still requires further research and breakthroughs. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a dual-mode optoelectronic device integrating photosynaptic and photodetector functions, as well as a method for its fabrication, thereby solving the problems in the prior art.

[0005] The objective of this invention can be achieved through the following technical solutions: A dual-mode optoelectronic device integrating photosynaptic and photodetector functions includes: an n-type GaN nanowire structure disposed on a substrate; A CsPbBr3 quantum dot layer is set on the surface of an n-type GaN nanowire structure, forming a CsPbBr3 / GaN heterojunction. And, an electrode lead-out terminal electrically connected to the CsPbBr3 / GaN heterojunction.

[0006] Furthermore, the substrate material is Si.

[0007] Furthermore, the CsPbBr3 quantum dot layer covers the surface of the nanowires in the GaN nanowire structure and fills the gap regions between the nanowires.

[0008] The fabrication method of the aforementioned dual-mode optoelectronic device integrating photosynaptic and photodetector functions includes the following steps: GaN nanowire structures are grown on a substrate; CsPbBr3 quantum dot solution was spin-coated onto the surface of the GaN nanowire structure and then annealed. Electrode leads are formed on the annealed sample, and the desired result is obtained.

[0009] Furthermore, the spin coating speed is 1000~4000 rpm, and the spin coating time is 20~120 s.

[0010] Furthermore, the annealing temperature is 60~150℃, and the annealing time is 0.5~2h.

[0011] Furthermore, the concentration of the CsPbBr3 quantum dot solution is 2~5 mg / mL.

[0012] A dual-mode optoelectronic system combining photosynapse and photodetector, comprising: Electrolyte tank and electrolyte medium disposed within the electrolyte tank; The aforementioned optoelectronic device is at least partially immersed in the electrolyte medium; The counter electrode and the reference electrode are in contact with the electrolyte medium; In addition, an external test circuit is provided, which is electrically connected to the electrode leads of the optoelectronic device, the counter electrode, and the reference electrode; wherein, the external test circuit includes a switching circuit, which is used to control the circuit in which the optoelectronic device is located to switch between a closed state and an open state.

[0013] Furthermore, the external test circuit also includes a measurement circuit, which is configured to: When the switching circuit closes the loop, the photocurrent signal of the optoelectronic device is acquired. When the switching circuit puts the circuit in an open-circuit state, it acquires the open-circuit potential change of the photoelectric device relative to the reference electrode, and / or acquires the open-circuit voltage between the photoelectric device and the counter electrode.

[0014] The above-mentioned dual-mode optoelectronic device integrating photosynaptic and photodetector functions is applied in ultraviolet light signal detection.

[0015] The beneficial effects of this invention are: 1. This invention incorporates a CsPbBr3 quantum dot layer on the surface of an n-type GaN nanowire structure, which together form the CsPbBr3 / GaN heterojunction working electrode. In closed-loop mode, the CsPbBr3 quantum dot layer, acting as an excellent light absorption and carrier generation layer, combined with the built-in electric field at the heterojunction interface, significantly improves the separation and transport efficiency of photogenerated carriers. Compared with bare GaN control devices, the device of this invention exhibits a significantly higher photoresponse current, stronger photoresponse output capability, and significantly improved photodetector performance.

[0016] 2. The device adopts a three-electrode system consisting of a working electrode, a counter electrode (platinum electrode), and a reference electrode (silver chloride electrode) immersed in an electrolyte medium. It also performs hard switching between closed and open circuits through a switching circuit. The closed circuit is used to collect short-circuit current, and the open circuit is used to collect open-circuit voltage. The test boundary conditions are changed entirely by external physical switching. It successfully overcomes the defect of existing photosynaptic devices that must rely on the continuous application of external bias voltage when switching modes. It not only takes into account both optical sensing and optical memory functions in the same device, but also significantly reduces the overall power consumption of the device.

[0017] 3. When the switching circuit is in an open-circuit state (photosynaptic mode), this invention extracts the open-circuit potential change of the working electrode relative to the reference electrode (or the open-circuit voltage between the working electrode and the counter electrode) as the output signal. In the open-circuit state, photogenerated carriers cannot be discharged, and are thus forced to accumulate and slowly release at the heterojunction interface and electrolyte interface (electric double layer). This endows the device with a macroscopic decay-maintaining characteristic, enabling it to perfectly exhibit the cumulative response to light pulse stimulation, paired pulse facilitation (PPF), and synaptic plasticity characteristics such as forgetting / relearning, fully meeting the application requirements of brain-like visual information processing.

[0018] 4. The fabrication method of the device of this invention mainly includes cleaning the substrate, spin-coating a CsPbBr3 solution (2~5 mg / mL) at a speed of 1000~4000 rpm to form a film, and performing low-temperature annealing at 60~150℃. The use of a full solution method combined with low-temperature heat treatment avoids the reliance on expensive equipment such as high vacuum and high-temperature deposition in traditional semiconductor processes. This makes the entire fabrication process simple, with high material utilization, low cost, and good reproducibility, making it extremely suitable for subsequent large-scale promotion and practical application. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the dual-mode optical synapse and photodetector device and its test structure prepared in Embodiment 1 of the present invention; Figure 2 This is a comparative schematic diagram showing the change of current over time in the devices prepared in Embodiments 1 and 2 of the present invention under two light pulses. The duration and interval of the light pulses are both 10 seconds. Figure 3 This is a comparative schematic diagram showing the voltage change over time of the devices prepared in Embodiments 1 and 2 of the present invention under five light pulses. The duration and interval of the light pulses are both 1 second. Figure 4 The voltage changes of the device prepared in Embodiment 1 of the present invention under light pulse durations of 1 second, 2.5 seconds, 4.5 seconds and 7 seconds; Figure 5 This refers to the voltage variation of the device prepared in Embodiment 1 of the present invention under pulses of different optical power; Figure 6 This refers to the voltage change of the device prepared in Embodiment 1 of the present invention under different pulse numbers; Figure 7 This is a schematic diagram showing the change of photocurrent over time in the device prepared in Embodiment 1 of the present invention under different optical powers; Figure 8 This is a schematic diagram showing the change of the paired pulse facilitation index (PPF) of the device prepared in Embodiment 1 of the present invention with the pulse time interval; Figure 9 This is a simulation diagram of the optical learning forgetting behavior of the device prepared in Embodiment 1 of the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] This invention proposes a dual-mode optoelectronic device combining photosynthesis and photodetection, comprising: an n-type GaN nanowire structure disposed on a substrate and a CsPbBr3 quantum dot layer disposed on its surface, wherein the CsPbBr3 quantum dot layer and the n-type GaN nanowire structure constitute a CsPbBr3 / GaN heterojunction.

[0023] The CsPbBr3 quantum dot layer covers the surface of the nanowires in the GaN nanowire structure and fills the gap regions between the nanowires. The fabrication method of the dual-mode device of photosynapse and photodetector described in this invention can be carried out according to the following steps: Step 1: Using plasma-assisted molecular beam epitaxy (MBE) technology, GaN nanowire arrays are grown on Si substrates to form n-type GaN nanowire structures. Step 2: Spin-coat a CsPbBr3 quantum dot solution (concentration of 2-5 mg / mL) onto an n-type GaN nanowire substrate; spin-coat at a speed of 1000-4000 rpm for 20-120 s.

[0024] Step 3: Place the above sample in a tubular furnace and anneal it under an inert gas to obtain a CsPbBr3 / GaN dual-mode optoelectronic device for photosynthesis and photodetector; the annealing temperature is 60-150℃ and the annealing time is 0.5-2h.

[0025] like Figure 1 As shown, this invention also proposes a device testing structure. The device, serving as a working electrode, includes: an electrolyte tank and an electrolyte solution disposed therein, a three-electrode system immersed in the electrolyte solution, and an external testing circuit. The three-electrode system includes: a working electrode, a counter electrode, and a reference electrode, wherein the counter electrode is a platinum electrode, and the reference electrode is a silver chloride reference electrode (Ag / AgCl). The testing structure is formed by assembling the working electrode, the platinum counter electrode, and the Ag / AgCl reference electrode in the electrolyte tank. The dual-mode optoelectronic device of the present invention achieves working mode switching through an external test circuit. The external test circuit includes a measurement circuit and a switching circuit. The switching circuit is used to control the circuit where the optoelectronic device is located to switch between a closed state and an open state: when the switching circuit controls the circuit to be closed, the measurement circuit collects the photocurrent signal of the working electrode, which is manifested as a current mode, i.e., photodetector mode; when the switching circuit controls the circuit to be open, the measurement circuit collects the change in photovoltage / open potential of the working electrode relative to the reference electrode, which is manifested as a voltage mode, i.e., photosynaptic mode.

[0026] In current mode, the CsPbBr3 quantum dot layer serves as both a light absorption and carrier generation layer. Combined with the CsPbBr3 / GaN heterojunction interface, it enhances the separation and transport efficiency of photogenerated carriers, thereby improving photoelectric detection performance. In voltage mode, photogenerated carriers accumulate and release at the heterojunction and electrolyte interfaces, giving the device output characteristics such as attenuation retention and cumulative response, thus achieving synaptic-like plasticity and memory characterization.

[0027] The electrolyte solution is PBS buffer solution. The platinum counter electrode is a platinum sheet or platinum mesh.

[0028] The technical solution of the present invention will be described below through the following embodiments, and the sources of the relevant raw materials in the embodiments are as follows: CsPbBr3 quantum dot solution: The CsPbBr3 quantum dots were purchased from Guangzhou Periodic Table Biomaterials Co., Ltd., with a concentration of 5 mg / ml. They were stored in the dark and at a low temperature of 3-4℃. Before use, they were brought to room temperature and thoroughly mixed.

[0029] Platinum counter electrode: Purchased from Zhengzhou Tuobo Instrument Equipment Co., Ltd.: Pt 10 10 Platinum mesh electrode.

[0030] Ag / AgCl reference electrode: Purchased from Topbo Instrument Equipment Co., Ltd.: R0302 silver / silver chloride 4mm 45mm.

[0031] The electrolyte solution was prepared by adding 1g of phosphate buffer powder to 100ml of water and stirring until homogeneous; the phosphate buffer powder (1×PBS, calcium and magnesium-free) was purchased from Xunbei Biotechnology / CC0002.

[0032] Example 1 This embodiment proposes a dual-mode optoelectronic device integrating photosynaptic and photodetector functions, and its fabrication method includes the following steps: Step 1: Use a 1cm×1cm Si substrate as a base. Thoroughly clean the Si substrate with acetone and methanol solvent to remove organic contaminants. Then, use 10% hydrofluoric acid to remove the native oxides on the substrate. Finally, perform in-situ annealing of the substrate at 750℃ to resolve the residual oxides. Then, under sufficient nitrogen conditions, GaN nanowire arrays were grown on a planar Si substrate using plasma-assisted molecular beam epitaxy (MBE) technology; in step 2, the CsPbBr3 quantum dot solution was taken out and allowed to stand at room temperature until it returned to room temperature, and then it was thoroughly mixed by shaking (in this embodiment, shaking was done by hand). Step 3: Take 10 μL of CsPbBr3 quantum dot solution with a pipette and spin-coat it onto n-GaN at 2000 rpm for 60 s. Step 4: Place the spin-coated sample into a tube furnace, first evacuate it, then fill it with nitrogen, and anneal it at 100°C for 1 hour under inert gas conditions to obtain a CsPbBr3 / GaN nanowire device (dual-mode optoelectronic device).

[0033] Example 2 To verify the improved performance of the CsPbBr3 / GaN heterojunction device described in Example 1 in both photodetector and photosynaptic dual-mode, Example 2 provides a bare n-GaN nanowire device (also a GaN nanowire array grown on a Si substrate).

[0034] The only difference between the fabrication process of the optoelectronic device and that of Example 1 is that the introduction steps of CsPbBr3 material (steps 2 and 3) are omitted, while the remaining steps and process parameters are the same as those in Example 1.

[0035] Example 3 In this embodiment, the devices prepared in Example 1 and Example 2 were experimentally tested; like Figure 1 As shown, the test structure used in this embodiment includes: an electrochemical workstation, an electrolytic cell, an electrolyte solution, a working electrode, a platinum counter electrode, and a reference electrode; the working electrode is either the CsPbBr3 / GaN nanowire device prepared in Example 1 or the bare n-GaN nanowire device prepared in Example 2. The specific setup process for the test structure is as follows: First, an electrolyte solution, namely phosphate buffer solution (PBS), is injected into the electrolyte bath. Then, the CsPbBr3 / GaN device prepared in Example 1 is fixed in the electrolyte bath as the working electrode, so that its effective working area is in full contact with the electrolyte solution. At the same time, a platinum electrode as the counter electrode and a silver chloride electrode (Ag / AgCl) as the reference electrode are inserted into the electrolyte solution respectively, forming a three-electrode system with the working electrode.

[0036] The working electrode, counter electrode, and reference electrode are then connected to their respective interfaces on the electrochemical workstation. An external switching circuit is introduced between the working electrode and the electrochemical workstation to switch between test modes. When the external circuit is closed, a closed loop is formed and the photocurrent signal is acquired; when the external circuit is open, an open circuit is formed and the photovoltage signal is acquired.

[0037] The electrochemical workstation is electrically connected to the working electrode and the platinum electrode, and the test mode is switched by switching the external circuit: when the external circuit is closed, the current signal is collected to characterize the photoelectric detection performance; when the external circuit is open, the voltage signal is collected to characterize the plasticity and memory effect of the photosynapse.

[0038] The test items include: 1) Comparative test of current change over time for the devices prepared in Example 1 and Example 2 under two light pulses; The testing process included: applying two optical pulse stimuli to the device of Example 1, with an optical power of 0.02 mW, a duration of 10 s for each pulse, and an interval of 10 s between the two pulses, and recording the current changes. The same steps were performed on the device of Example 2.

[0039] Test results are as follows Figure 2 As shown, under the same test conditions, the photoresponse current of the CsPbBr3 / GaN device in Example 1 is significantly higher than that of the bare n-GaN nanowire device in Example 2. Both devices can recover to the dark-state current level after the light is turned off, indicating that the heterojunction formed by CsPbBr3 modification can significantly enhance the photoelectric detection performance of the device.

[0040] 2) Comparative test of voltage change over time for the devices prepared in Example 1 and Example 2 under five light pulses; The testing process included applying five light pulses to the device, with a light power of 0.02 mW, a duration of 1 s for each light pulse, and a 1 s interval between two light pulses, and recording the voltage changes. The same steps were performed on the device in Example 2.

[0041] Test results are as follows Figure 3 As shown, under the same test conditions, the voltage response amplitude of the CsPbBr3 / GaN device in Example 1 is significantly higher than that of the bare n-GaN nanowire device in Example 2. Moreover, the voltage decays slowly and retains a certain residual value after the light stimulation is stopped, indicating that the photosynaptic response and memory retention characteristics of the CsPbBr3 modified device are more significant.

[0042] 3) Voltage changes of the device prepared in Example 1 under light pulse durations of 1 second, 2.5 seconds, 4.5 seconds, and 7 seconds; The testing process includes: applying a light pulse to the device once with a power of 0.02mw and a pulse duration of 1s, and recording the voltage change; applying another light pulse to the device once with a pulse duration of 2.5s, and recording the voltage change; repeating the steps, and then testing the voltage change under light pulse durations of 4.5s and 7s respectively.

[0043] Test results are as follows Figure 4 As shown, it can be seen that the CsPbBr3 / GaN device in Example 1 produces a significant voltage response under different optical pulse durations (1s, 2.5s, 4.5s, 7.5s); and the longer the pulse duration, the stronger the voltage response and the slower the decay, indicating that the response intensity of the device can be controlled by the stimulation duration.

[0044] 4) Voltage variation of the device prepared in Example 1 under pulses of different optical power; The testing process included: applying five light pulses to the device with a power of 0.01 mW, each pulse lasting 1 s, and an interval of 1 s between pulses, recording the voltage changes. The procedure was repeated, but the light power was varied, and the voltage changes were tested at power levels of 0.02 mW, 0.05 mW, and 0.1 mW.

[0045] Test results are as follows Figure 5 As shown, it can be seen that the CsPbBr3 / GaN device in Example 1 generates a voltage response under different optical power excitation; and the voltage response increases with increasing optical power, indicating that the device has sensitive and adjustable output characteristics to changes in light intensity.

[0046] 5) Voltage variation of the device prepared in Example 1 under different optical pulse numbers; The testing procedure included: applying a single optical pulse to the device with a power of 0.02 mW, a duration of 1 s for each pulse, and a 1 s interval between pulses, and recording the voltage change. The procedure was repeated, changing only the number of optical pulses, to test the voltage change after three, five, and eight pulses of stimulation.

[0047] Test results are as follows Figure 6 As shown, it can be seen that the voltage response of the CsPbBr3 / GaN device in Example 1 gradually increases with the increase of the number of light pulses under stimulation of different numbers of light pulses (1, 3, 5, 8 times), which reflects the pulse accumulation effect and short-term memory behavior.

[0048] 6) The photocurrent of the device prepared in Example 1 changes over time under different optical powers; The testing process included: applying eight light pulses to the device of Example 1, with a light power of 0.01 mW, a duration of 10 s for each light pulse, and an interval of 10 s between two light pulses, and recording the current changes. The procedure was repeated, changing only the light power, to test the current changes at light powers of 0.03 mW, 0.1 mW, 0.5 mW, and 1 mW.

[0049] Test results are as follows Figure 7 As shown, it can be seen that under the same test conditions, the photocurrent increases synchronously with the increase of optical power and the waveform remains stable, indicating that the photoelectric detection output of the device can be adjusted with the light intensity.

[0050] 7) The pairwise pulse facilitation index (PPF) of the device prepared in Example 1 varies with the pulse time interval; The testing process includes: calculating the PPF value under different light pulse intervals and performing fitting.

[0051] Test results are as follows Figure 8 As shown, it can be seen that the Paired Pulse Facilitation Index (PPFindex) of the device in Example 1 gradually decreases with the increase of the pulse interval time, and can be well characterized by the fitting curve, indicating that the device has obvious short-term synaptic plasticity (facilitation) characteristics.

[0052] 8) Simulation of the optical learning forgetting behavior of the device prepared in Example 1; The experimental procedure included: applying twenty light pulses to the device of Example 1, turning off the light for 30 seconds, and then applying ten more light pulses. The light power was 0.02 mW, the duration of each light pulse was 1 second, and the interval between two light pulses was 1 second. The voltage changes were recorded.

[0053] Experimental results are as follows Figure 9 As shown, it can be seen that the voltage of the device in Example 1 gradually accumulates and tends to saturate after continuous light pulse stimulation; after the stimulation stops, the voltage slowly decays over time, exhibiting a "forgetting" process. When light pulses are applied again, the voltage can be quickly restored and the response enhanced, demonstrating the characteristic of transitioning from short-term memory to more stable memory.

[0054] In summary, this invention provides a dual-mode optoelectronic device combining photosynaptic and photodetector technologies, along with its fabrication method. The device uses GaN as a substrate, forming a heterojunction structure by introducing CsPbBr3 onto its surface, and operates in an electrolyte environment. The operating mode is switched via an external circuit switch: when the external circuit is closed, a current signal is output for photodetector operation; when the external circuit is open, a voltage signal is output for photosynaptic response and memory characterization. Compared to a bare GaN control device, this device exhibits a stronger photoresponse output and can achieve adjustable response and accumulation effects under different optical power, pulse duration, and pulse count conditions. It also possesses synaptic plasticity characteristics such as paired pulse facilitation, forgetting, and relearning. The fabrication method is simple, low-cost, and highly reproducible, making it suitable for applications such as low-power photodetector and neuromorphic visual information processing.

[0055] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0056] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A dual-mode optoelectronic device integrating photosynaptic and photodetector functions, characterized in that, include: n-type GaN nanowire structure disposed on substrate; A CsPbBr3 quantum dot layer is set on the surface of an n-type GaN nanowire structure, forming a CsPbBr3 / GaN heterojunction. And, an electrode lead-out terminal electrically connected to the CsPbBr3 / GaN heterojunction.

2. The dual-mode optoelectronic device integrating photosynaptic and photodetector functions according to claim 1, characterized in that, The substrate material is Si.

3. The dual-mode optoelectronic device integrating photosynaptic and photodetector functions according to claim 2, characterized in that, The CsPbBr3 quantum dot layer covers the surface of the nanowires in the GaN nanowire structure and fills the gap regions between the nanowires.

4. The method for fabricating the dual-mode optoelectronic device integrating photosynaptic and photodetector functions as described in any one of claims 1-3, characterized in that, Includes the following steps: GaN nanowire structures are grown on a substrate; CsPbBr3 quantum dot solution was spin-coated onto the surface of the GaN nanowire structure; And then perform annealing; Electrode leads are formed on the annealed sample, and the desired result is obtained.

5. The method for fabricating a dual-mode optoelectronic device integrating photosynaptic and photodetector functions according to claim 4, characterized in that, The spin coating speed is 1000~4000 rpm, and the spin coating time is 20~120 s.

6. The method for fabricating a dual-mode optoelectronic device integrating photosynaptic and photodetector functions according to claim 4, characterized in that, The annealing temperature is 60~150℃, and the annealing time is 0.5~2h.

7. The method for fabricating a dual-mode optoelectronic device integrating photosynaptic and photodetector functions according to claim 4, characterized in that, The concentration of the CsPbBr3 quantum dot solution is 2~5 mg / mL.

8. A dual-mode optoelectronic system combining photosynapse and photodetector, characterized in that, include: Electrolyte tank and electrolyte medium disposed within the electrolyte tank; The optoelectronic device according to any one of claims 1-3, wherein the optoelectronic device is at least partially immersed in the electrolyte medium; The counter electrode and the reference electrode are in contact with the electrolyte medium; In addition, an external test circuit is provided, which is electrically connected to the electrode leads of the optoelectronic device, the counter electrode, and the reference electrode; wherein, the external test circuit includes a switching circuit, which is used to control the circuit in which the optoelectronic device is located to switch between a closed state and an open state.

9. A dual-mode optoelectronic system of photosynapse and photodetector according to claim 8, characterized in that, The external test circuit also includes a measurement circuit, which is configured to: When the switching circuit closes the loop, the photocurrent signal of the optoelectronic device is acquired. When the switching circuit puts the circuit in an open-circuit state, it acquires the open-circuit potential change of the photoelectric device relative to the reference electrode, and / or acquires the open-circuit voltage between the photoelectric device and the counter electrode.

10. The application of the dual-mode optoelectronic device integrating photosynaptic and photodetector functions as described in any one of claims 1-3 in ultraviolet light signal detection.

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