Mixed-dimensional nano-structure photoelectric detector, preparation method thereof and brain-like computing application of mixed-dimensional nano-structure photoelectric detector

Abstract

The invention discloses a mixed-dimensional nanostructure photoelectric detector and a preparation method and brain-like calculation application thereof, and belongs to the field of optoelectronics. A one-dimensional first semiconductor material nanorod and a three-dimensional second semiconductor material particle layer are constructed on a substrate to jointly form a mixed-dimensional nanostructure; the mixed-dimensional nanostructure is used as a heterostructure to build a built-in electric field for promoting carrier separation and photoelectric transmission; and the electrode is arranged on the substrate. The photoelectric detection performance is remarkably improved, the artificial synapse device is successfully prepared, the preparation process of the device is simple, the cost is low, and the device has a huge application prospect in the fields of neuromorphic devices and optical communication systems.

Description

Technical Field

[0001] The present invention relates to the field of optoelectronics, and more specifically, to a mixed-dimensional nanostructure photoelectric detector, a preparation method thereof, and brain-like computing applications. Background Art

[0002] Almost 70% of the information humans receive from the outside world is obtained through visual perception. Various photodetectors that convert light stimuli into electrical signals are an extension of human vision. With the rapid development of artificial intelligence technology and advanced robotic systems that can work under various environmental conditions in the future, there is an urgent need for excellent and intelligent light detection devices. In recent years, photodetectors composed of metal organic frameworks have begun to emerge. Metal organic frameworks (MOFs) are formed by inorganic metal clusters and organic linker ligands. They are a new type of hybrid photodetector that combines the advantages of inorganic and organic photodetectors, and do not require complex and expensive manufacturing processes. They can be directly prepared into simple photodetectors. Its morphology is diverse, so it can also form one-dimensional, two-dimensional and three-dimensional photodetectors. In particular, two-dimensional photodetectors have been successfully used in the manufacture of optoelectronic devices due to their highly delocalized π-electron system, good electron transfer and good light capture performance. However, effective charge separation under illumination is still a challenge for MOFs photodetectors, especially this kind of photoconductor often has the disadvantages of poor conductivity, slow photoresponse and low sensitivity, which seriously limits the performance improvement of photodetectors. A particularly effective way to improve the performance of MOFs photodetectors is to combine MOFs layers with other functional materials. This method facilitates the formation of heterojunctions. The in-situ growth of heterojunctions provides the possibility of enhancing interface interconnection and promoting carrier transport, which can effectively promote the separation of photogenerated charges and thus improve the photoelectric performance. Mixed-dimensional nanostructures can inherit material advantages or make up for defects, and usually show excellent stability. Therefore, it is a good choice in the preparation of optoelectronic devices.

[0003] However, how to construct a relatively stable nanostructure system and achieve excellent photoelectric detection performance remains a difficult problem. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a mixed-dimensional nanostructure photodetector and a preparation method and brain-like computing application thereof. By in-situ growing MOFs particles on zinc oxide nanorods, a detection device with better performance than MOFs monomers is obtained; and the unique material dimension of the device enables it to also have photoelectric synapse function, which can imitate the short-term plasticity (STP) and long-term plasticity (LTP) behavior of human synapses, and can be used as a unit device in a neuromorphic computing architecture system.

[0005] The object of the present invention is achieved through the following solutions:

[0006] A hybrid nanostructure photoelectric detector, comprising:

[0007] substrate;

[0008] A one-dimensional nanorod of a first semiconductor material and a three-dimensional particle layer of a second semiconductor material are constructed on a substrate to form a mixed-dimensional nanostructure;

[0009] The mixed-dimensional nanostructure is used as a heterostructure to build a built-in electric field to promote carrier separation and photoelectric transmission;

[0010] The electrode is arranged on the substrate.

[0011] Furthermore, the first semiconductor material nanorods include ZnO nanorods, and the three-dimensional second semiconductor material particle layer includes three-dimensional Cu 3 (HHTP) 2 Thin film layer, using the light-conducting and wide bandgap of ZnO nanorods, and three-dimensional Cu 3 (HHTP) 2 Construct a built-in electric field.

[0012] Furthermore, the substrate comprises a FTO glass substrate.

[0013] Furthermore, the electrode comprises interdigitated electrodes, which are engraved at the center of the substrate.

[0014] A hybrid-dimensional nanostructure photodetector for use in brain-like computing, wherein any of the hybrid-dimensional nanostructure photodetectors described above is used as a photoelectric neuromorphic device in brain-like computing.

[0015] A method for preparing a hybrid nanostructure photoelectric detector, comprising preparing the hybrid nanostructure photoelectric detector as described above according to the following steps:

[0016] Step 1, prepare a ZnO nanoparticle suspension, spin-coat it on a clean substrate, and calcine it at a temperature range of 200-300°C for 20-30 minutes to ensure the upright growth of ZnO nanorods;

[0017] Step 2, preparing a precursor solution, preparing an equimolar solution of zinc nitrate and hexamethylenetetramine in deionized water, stirring and mixing at room temperature to obtain a uniform solution; placing the substrate coated with ZnO nanoparticle seeds in a container containing the precursor solution, and then covering the polytetrafluoroethylene cup with aluminum foil and placing it in an oil bath pot in the range of 90-100° C. for 6-8 hours to obtain upright growing zinc oxide nanorods;

[0018] Step 3: Alternately immerse the substrate with zinc oxide nanorods in two precursor solutions. The first precursor solution is Cu(OAc)2 The first precursor solution was HHTP solution, and the immersion time was 20 to 30 minutes. The second precursor solution was HHTP solution, and the immersion time was 10 to 20 minutes. After each step, ethanol was used to remove the unreacted precursor, and multiple cycles were performed. Finally, Cu was grafted onto the prepared ZnO nanorods. 3 (HHTP) 2 layer, that is, one-dimensional zinc oxide nanorods / three-dimensional MOFs:Cu 3 (HHTP) 2 Heterojunction photodetector.

[0019] Further, in step 1, the calcination at a temperature range of 200-300° C. for 20-30 mins specifically includes: calcination at a temperature range of 300° C. for 30 mins.

[0020] Further, in step 2, placing it in an oil bath at 90-100° C. for 6-8 hours specifically includes placing it in an oil bath at 95° C. for 6 hours.

[0021] Furthermore, in Cu(OAc) 2 The immersion time in the solution is 20 minutes; the immersion time in the HHTP solution is 10 minutes.

[0022] Furthermore, in step 1, the preparation of the ZnO nanoparticle suspension specifically includes the following sub-steps:

[0023] Prepare 0.01M zinc acetate methanol solution at 60°C and 0.09M NaOH solution at the same time, stir at room temperature for 20-30 minutes;

[0024] Then, NaOH solution was used as a reducing agent, heated at 60°C for 5-7 min, keeping the two solutions at the same temperature, and then added to the zinc acetate solution;

[0025] Finally, the NaOH solution was added dropwise to the zinc acetate solution, and the mixture was stirred at 60 °C for 2 h using a magnetic stirrer to obtain stable ZnO nanoparticles.

[0026] The beneficial effects of the present invention include:

[0027] (1) The preparation method provided by the present invention adopts one-dimensional / three-dimensional in-situ growth design when designing the material dimension. ZnO and Cu 3 (HHTP) 2 The formation of a heterojunction and then the built-in electric field established at the interface, the contact area between the nanorods and MOFs balls is large and controllable, and the fast transmission between the interfaces can effectively promote the separation of photogenerated carriers and increase the photocurrent.

[0028] (2) The present invention designs a method for preparing zinc oxide nanorods / Cu with simple process and low cost. 3 (HHTP) 2 Heterojunction photodetectors, introducing a simple hydrothermal method to fabricate ZnO nanorods and an immersion method to fabricate Cu 3 (HHTP) 2 The material replaces p-type / n-type silicon in traditional photodetectors, avoiding the use of high-temperature diffusion and ion implantation processes, as well as expensive instruments and equipment, and reducing device preparation costs.

[0029] (3) The zinc oxide nanorods / Cu 3 (HHTP) 2 The performance of hybrid dimensional photodetector is significantly higher than that of Cu 3 (HHTP) 2 The response rate of the single-cell device has been increased by 6 orders of magnitude. In addition, the photodetection device also has photoelectric synaptic properties, which can simulate the short-term and long-term memory functions of the human brain. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0031] Figure 1 The zinc oxide nanorods / Cu 3 (HHTP) 2 Schematic diagram of the structure of a hybrid dimensional photoelectric detection device;

[0032] Figure 2 For different concentrations of Cu(OAc) 2 SEM images of composite materials obtained in solution (representing different concentrations of MOFs);

[0033] Figure 3 For the preparation of one-dimensional (zinc oxide nanorods) / three-dimensional (MOFs:Cu 3 (HHTP) 2 )TEM image of hybrid dimensional photodetector;

[0034] Figure 4 Simulation of the electric field of different structures under 405nm light;

[0035] Figure 5 Cu 3 (HHTP) 2 , ZnO nanorods, ZnO nanorods / Cu3 (HHTP) 2 Comparison of the photoelectric performance response rate and stable photoelectric response of the three heterojunctions, where (a) is the performance comparison of the three, and (b) is the stable switching response;

[0036] Figure 6 It is a plasticity curve diagram of the optoelectronic artificial synaptic device designed according to the method of the present invention under different light powers;

[0037] Figure 7 A curve diagram of the process from short-term memory to long-term memory of the optoelectronic artificial synaptic device designed for the method of the present invention;

[0038] Figure 8 A curve graph obtained by testing the short-term plasticity double pulse facilitation (PPF) of an optoelectronic artificial synaptic device designed according to the method of the present invention;

[0039] Fig. 9 Visualization of memory and forgetting for a 3x3 array device with L-shaped illumination;

[0040] In the figure, 1-FTO glass, 2-interdigitated electrodes, 3-composite material ZnO nanorods / Cu 3 (HHTP) 2 , 4-405nm laser irradiation. DETAILED DESCRIPTION

[0041] All features disclosed in all embodiments in this specification, or steps in all methods or processes implicitly disclosed, except for mutually exclusive features and / or steps, can be combined and / or expanded or replaced in any manner.

[0042] In view of the current situation in the background, the inventors of the present invention have experienced creative thinking and believe that: in the biological world, rhizobia can invade the roots from the root hairs of leguminous plants to form nodules, and become branched polymorphic cells in the nodules to form bacteriomorphs. As a result, the root system is covered with nodular rhizobia. It is precisely because of this simple invasion method and large root surface area that the more contact surfaces between rhizobia and the root system, the more nutrients the two can provide to each other, and the more they promote the common growth of the symbiont. Inspired by this, the inventors of the present invention believe that this one-dimensional / three-dimensional nanostructure system design is expected to be used to construct high-performance optoelectronic devices.

[0043] On the other hand, building multifunctional light detection devices is also an emerging direction that scientists are exploring. The human brain operates in an efficient and low-power parallel computing mode, which has attracted much attention in recent years and has become an object of imitation. The key to these remarkable characteristics lies in the basic unit that constitutes the human brain's nervous system, namely the biological synapse. Therefore, the development of artificial synaptic devices that can simulate the behavior of biological synapses has become one of the research topics of neuromorphic computing. Photoelectric synapses can integrate information perception, processing, and memory in one device, and have become a promising candidate for the development of artificial visual systems. The development of optoelectronic neural devices has brought new opportunities for the development of brain-like devices.

[0044] In a preferred embodiment, it particularly relates to the field of optoelectronics and neuromorphic device technology, and specifically to providing a photodetector based on zinc oxide and metal organic framework materials, a photoelectric artificial synapse device and a preparation method thereof.

[0045] Figure 1 The zinc oxide nanorods / Cu 3 (HHTP) 2 The structure of the hybrid dimensional photodetector, 1 is FTO glass, 2 is the interdigitated electrode, 3 is the composite material ZnO nanorod / Cu 3 (HHTP) 2 , 4 is 405nm laser irradiation.

[0046] Figure 2 The MOFs concentration in the embodiment is optimized to obtain the composite material, Cu(OAc) 2 The higher the solution concentration, the more MOFs (shown as small spheres) around the zinc oxide nanorods become, the larger they are, and the more irregular they become. In order to obtain a one-dimensional / three-dimensional assembly, we experimentally selected a moderate concentration of 5 mM.

[0047] Figure 3 In the embodiment, one-dimensional (ZnO nanorods) / three-dimensional (MOFs:Cu 3 (HHTP) 2 ) TEM image of the hybrid dimensional photodetector (scale is 100nm), such as Figure 3 As shown, Cu 3 (HHTP) 2 The particles are red, and the zinc oxide nanorods are green. After stitching the two images, the red Cu 3 (HHTP) 2 The particles were perfectly loaded on the zinc oxide nanorods, fully demonstrating the success of this one-dimensional / three-dimensional design.

[0048] Figure 4 The simulation results of finite-difference time domain (FDTD) are shown in Figure 2. To illustrate that the design of one-dimensional / three-dimensional hybrid is successful, one-dimensional ZnO and three-dimensional Cu3 (HHTP) 2 , one-dimensional (zinc oxide nanorods) / three-dimensional (MOFs:Cu 3 (HHTP) 2 ) and one-dimensional (ZnO nanorods) / two-dimensional (MOFs:Cu 3 (HHTP) 2 ) were fitted, and the results showed that the electric field was enhanced along the diameter of the nanowave. 3 (HHTP) 2 Compared with one-dimensional (ZnO nanorods) / three-dimensional (MOFs:Cu 3 (HHTP) 2 ) showed the largest electric field enhancement, indicating that the carrier transport is most favorable under this structural design. 3 (HHTP) 2 ) compared with the electric field of the 1D / 3D design.

[0049] Figure 5 The left side is a comparison chart of the response rate R. The response rate is a parameter that quantifies the sensitivity of the photodetector and can be expressed as the formula I ph represents the photocurrent intensity, P represents the light power density, and A is the light receiving area. Figure 5 It can be clearly seen that Cu 3 (HHTP) 2 The response rate of the monomer is much lower than that of ZnO nanorods / Cu 3 (HHTP) 2 The response rate of the heterojunction composite material shows that this strategy is feasible. The right side shows the stable photoelectric response under 405nm light when the bias voltage is 1V.

[0050] Figure 6 Through the photoelectric testing system, the switching time of the light source shutter is controlled (5s) to simulate neural stimulation. The synaptic plasticity curve of the device under 405nm light is tested as the test curve of synaptic plasticity. It can be seen that under different powers, the heterojunction device has short-term plasticity (STP) and long-term plasticity (LTP).

[0051] Figure 7 This is the photocurrent response under different light stimulation times. When the stimulation time is short, the current intensity is also small. When the stimulation time gradually increases, the current response also gradually increases, indicating that relearning the same thing can significantly improve memory ability, reflecting the process from short-term memory (STM) to long-term memory (LTM).

[0052] Figure 8By fitting the PPF index under different pulse intervals Δt (i.e., the ratio of current intensities under two consecutive light stimulations), the curve PPF = -0.06 + 6.43 × exp (-ΔT / 0.79) + 29.84 × exp (-ΔT / / 30.52) was obtained. C1 (6.43s) and C2 (29.84s) represent the initial facilitation amplitudes of the fast phase and the slow phase, respectively. τ1 (0.79ms) and τ2 (30.52ms) represent the characteristic relaxation times of the two phases, respectively. 1 =6.43s), C 2 = 29.84 s, τ1 = 0.79 ms, τ2 = 30.52 ms. Our results are in good agreement with the measured data of biological synapses.

[0053] Fig. 9 The current response of 9 devices in a 3x3 array under L-shaped irradiation (405nm) with a mask plate. During the forgetting process, after 120s of stimulation, the current intensity in the area with an irradiated area of ​​L decreased visibly within 130s. During the memory process, the area with an irradiated area of ​​L was stimulated for 120s, and the current intensity increased visibly within 130s, which perfectly reflects the process of memory and forgetting, just like the brain memory effect. Among them, the depth of color represents the magnitude of the current change in the current response.

[0054] The heterojunction optoelectronic artificial synaptic device provided by the present invention has strong plasticity, good memory effect, and excellent device stability, and can be applied to the field of neuromorphic computing of brain-like devices.

[0055] In summary, the present invention is inspired by the symbiotic system of the biological world, and the specific concept involves a method for preparing a hybrid nanostructure photodetector. Through the composite of one-dimensional zinc oxide nanorods and three-dimensional metal organic framework materials, the photodetection performance is significantly improved, and in a preferred embodiment, an artificial synaptic device that responds to ultraviolet light 405nm is successfully prepared. In addition, the preparation process of the present invention is simple and low-cost, and has great application prospects in the fields of neuromorphic devices and optical communication systems.

[0056] It should be noted that within the scope of protection defined in the claims of the present invention, the following embodiments can be combined and / or expanded or replaced in any logical way from the above specific implementation methods, such as disclosed technical principles, disclosed technical features or implicitly disclosed technical features.

[0057] Example 1

[0058] In one embodiment, the present invention provides a mixed-dimensional nanostructure photodetector, comprising:

[0059] substrate;

[0060] A one-dimensional nanorod of a first semiconductor material and a three-dimensional particle layer of a second semiconductor material are constructed on a substrate to form a mixed-dimensional nanostructure;

[0061] The mixed-dimensional nanostructure is used as a heterostructure to build a built-in electric field to promote carrier separation and photoelectric transmission;

[0062] The electrode is arranged on the substrate.

[0063] Example 2

[0064] In an optional embodiment, based on embodiment 1, the present invention further provides the following embodiment: the first semiconductor material nanorods include ZnO nanorods, the three-dimensional second semiconductor material particle layer includes three-dimensional Cu 3 (HHTP) 2 Thin film layer, using the light-conducting and wide bandgap of ZnO nanorods, and three-dimensional Cu 3 (HHTP) 2 Construct a built-in electric field.

[0065] In an optional embodiment, based on Embodiment 1, the present invention further provides the following embodiment: the substrate comprises a FTO glass substrate.

[0066] In an optional embodiment, based on embodiment 1, the present invention further provides the following embodiment: the interdigital electrodes are included and are engraved at the center of the substrate.

[0067] Example 3

[0068] A hybrid nanostructured photodetector for use in brain-like computing, wherein the hybrid nanostructured photodetector described in any one of Embodiment 1 or Embodiment 2 is used as a photoelectric neuromorphic device in brain-like computing.

[0069] Example 4

[0070] A method for preparing a hybrid nanostructured photoelectric detector, comprising preparing the hybrid nanostructured photoelectric detector described in Example 2 according to the following steps:

[0071] Step 1, prepare a ZnO nanoparticle suspension, spin-coat it on a clean substrate, and calcine it at a temperature range of 200-300°C for 20-30 minutes to ensure the upright growth of ZnO nanorods;

[0072] Step 2, preparing a precursor solution, preparing an equimolar solution of zinc nitrate and hexamethylenetetramine in deionized water, stirring and mixing at room temperature to obtain a uniform solution; placing the substrate coated with ZnO nanoparticle seeds in a container containing the precursor solution, and then covering the polytetrafluoroethylene cup with aluminum foil and placing it in an oil bath pot in the range of 90-100° C. for 6-8 hours to obtain upright growing zinc oxide nanorods;

[0073] Step 3: Alternately immerse the substrate with zinc oxide nanorods in two precursor solutions. The first precursor solution is Cu(OAc) 2 The first precursor solution was HHTP solution, and the immersion time was 20 to 30 minutes. The second precursor solution was HHTP solution, and the immersion time was 10 to 20 minutes. After each step, ethanol was used to remove the unreacted precursor, and multiple cycles were performed. Finally, Cu was grafted onto the prepared ZnO nanorods. 3 (HHTP) 2 layer, that is, one-dimensional zinc oxide nanorods / three-dimensional MOFs:Cu 3 (HHTP) 2 Heterojunction photodetector.

[0074] Example 5

[0075] In an optional embodiment, based on Example 4, in step 1, the calcination at a temperature range of 200-300°C for 20-30 mins specifically includes: calcination at a temperature range of 300°C for 30 mins.

[0076] Example 6

[0077] In an optional embodiment, based on Example 4, in step 2, placing it in an oil bath in the range of 90-100° C. for 6-8 hours specifically includes: placing it in an oil bath at 95° C. for 6 hours.

[0078] Example 7

[0079] In an alternative embodiment, based on Example 4, in Cu(OAc) 2 The immersion time in the solution is 20 minutes; the immersion time in the HHTP solution is 10 minutes.

[0080] Example 8

[0081] In an optional embodiment, based on Example 4, in step 1, the preparation of the ZnO nanoparticle suspension specifically includes the following sub-steps:

[0082] Prepare 0.01M zinc acetate methanol solution at 60°C and 0.09M NaOH solution at the same time, stir at room temperature for 20-30 minutes;

[0083] Then, NaOH solution was used as a reducing agent, heated at 60°C for 5-7 min, keeping the two solutions at the same temperature, and then added to the zinc acetate solution;

[0084] Finally, the NaOH solution was added dropwise to the zinc acetate solution, and the mixture was stirred at 60 °C for 2 h using a magnetic stirrer to obtain stable ZnO nanoparticles.

[0085] The above description is only the technical principle and preferred embodiment used in the present invention. It will be understood by those skilled in the art that the present invention is not limited to the specific embodiments described herein. It is possible for those skilled in the art to make various obvious changes, adjustments and substitutions without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may also include more other equivalent embodiments without departing from the principles and concepts of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A hybrid nanostructure photodetector, characterized in that: include: substrate; A one-dimensional nanorod of a first semiconductor material and a three-dimensional particle layer of a second semiconductor material are constructed on a substrate to form a mixed-dimensional nanostructure; The mixed-dimensional nanostructure is used as a heterostructure to build a built-in electric field to promote carrier separation and photoelectric transmission; The electrode is arranged on the substrate.

2. The hybrid nanostructure photodetector according to claim 1, characterized in that: The first semiconductor material nanorods include ZnO nanorods, and the three-dimensional second semiconductor material particle layer includes a three-dimensional Cu3(HHTP)2 thin film layer. The photoconductivity and wide band gap of the ZnO nanorods are used to construct a built-in electric field with the three-dimensional Cu3(HHTP)2.

3. The hybrid nanostructure photodetector according to claim 1, characterized in that: The substrate includes a FTO glass substrate.

4. The hybrid nanostructure photodetector according to claim 1, characterized in that: The device comprises interdigitated electrodes and is engraved at the center of the substrate.

5. A hybrid nanostructure photodetector for brain-like computing, characterized in that: The hybrid-dimensional nanostructure photodetector described in any one of claims 1 or 2 is used as a photoelectric neuromorphic device in brain-like computing.

6. A method for preparing a mixed-dimensional nanostructure photoelectric detector, characterized in that: The mixed-dimensional nanostructure photodetector according to claim 2 is prepared according to the following steps: Step 1, prepare a ZnO nanoparticle suspension, spin-coat it on a clean substrate, and calcine it at a temperature range of 200-300°C for 20-30 minutes to ensure the upright growth of ZnO nanorods; Step 2, preparing a precursor solution, preparing an equimolar solution of zinc nitrate and hexamethylenetetramine in deionized water, stirring and mixing at room temperature to obtain a uniform solution; placing the substrate coated with ZnO nanoparticle seeds in a container containing the precursor solution, and then covering the polytetrafluoroethylene cup with aluminum foil and placing it in an oil bath pot in the range of 90-100° C. for 6-8 hours to obtain upright growing zinc oxide nanorods; Step 3, alternately immersing the substrate with zinc oxide nanorods in two precursor solutions, the first precursor solution is Cu(OAc)2 solution, and the immersion time is 20 to 30 minutes; the second precursor solution is HHTP solution, and the immersion time is 10 to 20 minutes; washing with ethanol after each step to remove unreacted precursors, and performing multiple cycles; finally, a Cu3(HHTP)2 layer is grafted and grown on the prepared zinc oxide nanorods, thereby obtaining a one-dimensional zinc oxide nanorod / three-dimensional MOFs:Cu3(HHTP)2 heterojunction photodetector.

7. The method for preparing a mixed-dimensional nanostructure photodetector according to claim 6, characterized in that: In step 1, the calcination at a temperature range of 200-300° C. for 20-30 minutes specifically includes: calcination at a temperature range of 300° C. for 30 minutes.

8. The method for preparing a mixed-dimensional nanostructure photodetector according to claim 6, characterized in that: In step 2, placing it in an oil bath pot at 90-100° C. for 6-8 hours specifically includes placing it in an oil bath pot at 95° C. for 6 hours.

9. The method for preparing a mixed-dimensional nanostructure photodetector according to claim 6, characterized in that: The immersion time in the Cu(OAc)2 solution was 20 mins; the immersion time in the HHTP solution was 10 mins.

10. The method for preparing a mixed-dimensional nanostructure photodetector according to claim 6, characterized in that: In step 1, the preparation of the ZnO nanoparticle suspension specifically includes the following sub-steps: Prepare 0.01M zinc acetate methanol solution at 60°C and 0.09M NaOH solution at the same time, stir at room temperature for 20-30 minutes; Then, NaOH solution was used as a reducing agent, heated at 60°C for 5-7 min, keeping the two solutions at the same temperature, and then added to the zinc acetate solution; Finally, the NaOH solution was added dropwise to the zinc acetate solution, and the mixture was stirred at 60 °C for 2 h using a magnetic stirrer to obtain stable ZnO nanoparticles.

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