Photoelectric synapse transistor based on room temperature solution processing ultraviolet light crosslinking dielectric material and preparation method and application thereof

Abstract

The invention relates to a photoelectric synapse transistor of an ultraviolet light crosslinking dielectric material processed based on a room temperature solution, and a preparation method and application thereof, and belongs to the field of dielectric materials and optoelectronic devices. An ultraviolet light crosslinking organic dielectric material c-DPHA (the structural formula of the monomer DPHA is # imgabs0 #) processed by a room temperature solution is used as a dielectric layer of the synapse transistor, and the flexible photoelectric synapse transistor is developed by combining a photosensitive organic semiconductor layer. The synaptic transistor has a good synaptic function, and various characteristics of simulating a biological synaptic function can be realized by adjusting parameters of light pulses. Compared with the prior art, the photoelectric synapse transistor simplifies the manufacturing process, has the advantages of being short in time consumption, simple in structure, excellent in performance and the like, and can be integrated into a flexible synapse array to simulate the human brain memory learning and forgetting process; and a new thought is provided for the development of a low-cost artificial synapse technology and the integrated application of photoelectric detection and imaging, intelligent terminals, sensing chips, neuromorphic calculation and sensing, storage and calculation.

Description

Technical Field

[0001] The invention belongs to the field of dielectric materials and optoelectronic devices, and relates to a photoelectric synaptic transistor based on ultraviolet light cross-linking dielectric materials processed by room temperature solution, and a preparation method and application thereof. Background Art

[0002] With the rapid development of artificial intelligence (AI), computing needs are growing day by day. However, the traditional von Neumann architecture faces problems such as the inability to further reduce energy consumption and limited processing speed due to the serial structure of the processor and memory, and the data is transported back and forth between the two. It is difficult to meet the new requirements of the development of the intelligent era. In order to meet these challenges, the industry has begun to explore brain-like neuromorphic computing technology, which simulates the learning and decision-making process of the brain to achieve more flexible, efficient and intelligent electronic devices. As the hardware basis of neuromorphic computing, brain-like artificial synaptic devices can provide low-energy and high-efficiency parallel information processing capabilities by imitating the synaptic function in the biological nervous system. By simulating the function of biological synapses, new brain-like artificial synaptic devices can integrate perception, storage and computing functions, and are expected to meet the challenges of the surge in information data in the future.

[0003] Recently, the research on brain-like artificial synaptic devices has mainly focused on two types of device structures based on memristors and field effect transistors (FETs). Compared with memristor-based synaptic devices, artificial synaptic devices based on FET structures show more efficient output current regulation capabilities and improved linearity due to the introduction of an adjustable gate as the third terminal electrode. In particular, organic field effect transistors (OFETs) are gradually gaining attention due to their advantages such as light weight, good flexibility, low cost, and high transparency. Despite this, most of the current research on OFET-based artificial synapses uses conventional dielectric materials, such as silicon dioxide (SiO2) or polymethacrylate (PMMA), polystyrene (PS), etc. There are few studies based on ultraviolet light cross-linked dielectric materials processed by room temperature solutions, and further realizing biomimetic synaptic functions. In view of the industrialization needs of large-scale integration, it is particularly important to achieve the advantages of low temperature, energy saving, high efficiency and patternability in the processing of key component materials such as the dielectric layer of artificial optoelectronic synaptic devices.

[0004] At present, a common method is to prepare a polymer dielectric layer by solution spin coating and thermal annealing process to construct optoelectronic synaptic devices, so as to improve the film forming property and uniformity of the dielectric layer. However, the thermal annealing process involved in this method often requires a high temperature environment, which is contrary to the goal of pursuing low energy consumption and is not conducive to large-scale industrial development. Another effective strategy is to use UV light curing cross-linking technology to prepare the dielectric layer. This method can be carried out at room temperature, which simplifies the process flow and reduces energy consumption. However, it is still extremely challenging to achieve excellent transistor and synaptic performance while keeping the process simple, which limits the promotion of these devices in practical applications.

[0005] Therefore, the design and exploration of the development of new OFET-type photosynaptic transistors and their arrays based on UV-crosslinked dielectric thin film materials processed by room temperature solutions has important practical significance and has great potential in the fields of photoelectric detection, imaging, smart terminals, sensor chips, neuromorphic computing, and integrated sensing, storage and computing technology. Summary of the invention

[0006] In view of this, the object of the present invention is to provide a photosynaptic transistor based on room temperature solution processing ultraviolet light cross-linked dielectric materials and a preparation method and use thereof.

[0007] To achieve the above object, one aspect of the present invention provides a photosynaptic transistor, wherein the dielectric material of the photosynaptic transistor is a room temperature solution processed UV cross-linked dielectric material.

[0008] The ultraviolet light cross-linked dielectric material is an organic polymer dielectric material c-DPHA having a hydroxyl polar functional group. The DPHA monomer structural formula of the dielectric material is

[0009] Preferably, the photosynapse transistor comprises, from bottom to top, a substrate, a gate, a dielectric layer, a semiconductor layer, a source and a drain; a conductive channel with a micro-nano scale spacing is formed between the source and the drain.

[0010] Further preferably, the material of the substrate is any one or more of polyethylene terephthalate, polyethylene naphthalate, polyimide, polydimethylsiloxane, polycarbonate, polyvinyl alcohol, glass, silica / silicon (the silica / silicon can be achieved by oxidizing a layer of thin film silica on the surface of a silicon substrate) or sapphire.

[0011] More preferably, the material of the substrate is any one of polyethylene terephthalate, polyethylene naphthalate, and polyimide.

[0012] Further preferably, the material of the gate, source or drain is any one or more of gold, silver, aluminum, copper, chromium, platinum, titanium, nickel, indium tin oxide, fluorine-doped tin oxide, zinc aluminum oxide or conductive polymer;

[0013] The conductive polymer has a conjugated main electron system on its main chain and is a polymer material that achieves a conductive state through doping. The conductive polymer includes any one of polyaniline, polythiophene, polyacetylene, and 2,7-dioctyl[1]benzothiophene[3,2-b][1]benzothiophene.

[0014] More preferably, the material of the gate, source or drain is any one of indium tin oxide, gold, silver, aluminum or copper.

[0015] Further preferably, the material of the semiconductor layer is a conjugated polymer semiconductor material or an organic small molecule semiconductor material;

[0016] The conjugated polymer semiconductor material includes any one or more of poly 3-hexylthiophene or its derivatives, indocyanine dithiophene-benzothiadiazole copolymer, 7,7,8,8-tetracyanoquinodimethane-doped indocyanine dithiophene-benzothiadiazole copolymer, poly{4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']disulfide-2,6-diyl}{3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl} or its derivatives, and copolymers of terthiophene and perylene imide units; the organic small molecule semiconductor material includes any one or more of pentacene or its derivatives, 7,7,8,8-tetracyanoquinodimethane or its derivatives, and copper phthalocyanine.

[0017] Further preferably, the material of the semiconductor layer is a conjugated polymer semiconductor material; the conjugated polymer semiconductor material includes any one or more of poly 3-hexylthiophene or its derivatives, indolescenyl dithiophene-benzothiadiazole copolymer, 7,7,8,8-tetracyanoquinodimethane-doped indolescenyl dithiophene-benzothiadiazole copolymer, and copolymers of terthiophene and perylene imide units.

[0018] Another aspect of the present invention provides a photosynapse transistor array, which includes a plurality of photosynapse transistors arranged in an array, and the photosynapse transistor array is configured with at least four pairs of source and drain electrodes.

[0019] Another aspect of the present invention provides a method for preparing a photosynaptic transistor, the method comprising:

[0020] (1) obtaining a phototransistor substrate, and preparing a gate on the surface of the substrate; wherein the gate may be prepared by any one of vacuum thermal evaporation, atomic layer deposition, magnetron sputtering, spin coating, inkjet printing or screen printing;

[0021] (2) on the surface of the gate and the substrate, a dielectric layer based on a room temperature solution processed ultraviolet light cross-linked dielectric material is formed by any one of spin coating, blade coating or inkjet printing and cross-linked by room temperature photocuring;

[0022] (3) forming a semiconductor layer on the surface of the dielectric layer by any one of atomic layer deposition, vacuum thermal evaporation, magnetron sputtering, spin coating, blade coating or inkjet printing;

[0023] (4) On the surface of the semiconductor layer, a source electrode and a drain electrode are prepared by any one of vacuum thermal evaporation, atomic layer deposition, magnetron sputtering, spin coating, inkjet printing or screen printing, and a conductive channel with a micro-nano scale spacing is formed between the source electrode and the drain electrode, thereby obtaining a photosynaptic transistor.

[0024] Preferably, in step (2), when the dielectric layer is prepared on the surface of the gate and the substrate by a spin coating method, the mass fraction of the dielectric layer material in the solution used in the spin coating process is 10 to 50 wt.%, the mass fraction of the ultraviolet light initiator is 1 to 5 wt.%, the solvent is any one or more of methanol, ethanol or isopropanol, the spin coating speed is 500 to 4000 rpm, and the spin coating time is 30 to 90 s; the time for 365 nm wavelength ultraviolet light cross-linking after spin coating is 2 to 30 min, and the environment of the ultraviolet light cross-linking is room temperature atmospheric environment.

[0025] Further preferably, the mass fraction of the dielectric material in the solution used in the spin coating process is 20 to 45 wt.%, and the time of UV cross-linking after spin coating is 2 to 20 min.

[0026] More preferably, the concentration of the dielectric material in the solution used in the spin coating process is 25-40 wt.%, and the time of UV cross-linking after spin coating is 5-15 min.

[0027] Another aspect of the present invention provides the application of the photosynaptic transistor or the photosynaptic transistor array in the field of photoelectric detection and imaging, smart terminals, sensor chips, neuromorphic computing or sensing, storage and computing integrated technology.

[0028] The beneficial effects of the present invention are:

[0029] (1) The present invention discloses a photoelectric synaptic transistor based on ultraviolet light cross-linked dielectric materials, using c-DPHA, an organic polymer dielectric material based on room temperature solution processing and ultraviolet light curing characteristics, as the dielectric layer of the photoelectric synaptic transistor. The polar hydroxyl functional group of the ultraviolet light cross-linked dielectric material c-DPHA can serve as an interface trap between the semiconductor and effectively regulate the separation and recombination process of carriers, so that the flexible OFET based on this type of organic dielectric layer can simulate the basic functions of biological synapses and successfully realize a photoelectric synaptic transistor with efficient synaptic response. This new type of organic photoelectric synaptic device not only breaks through the traditional strategy of using solution spin coating combined with thermal annealing to prepare polymer dielectric layers, but also provides a new choice and beneficial ideas for high-performance artificial photoelectric synaptic devices.

[0030] (2) The photoelectric synaptic transistor of the present invention can realize the portable regulation capability of the device synaptic performance by regulating the parameters of light pulses and electrical pulses. The prepared OFET artificial synaptic device exhibits common biological synaptic functions such as excellent double pulse facilitation (PPF) and conversion from short-term memory (STM) to long-term memory (LTM), meeting the application requirements of information learning and memory functional photoelectric synapses, and has great potential in machine vision, deep learning and other aspects.

[0031] (3) The photosynaptic transistor and array of the present invention not only have excellent large-area processing uniformity and intrinsic flexibility based on UV-crosslinked dielectric materials, but also can realize a bionic visual system by simulating the characteristics of biological synapses. Based on these excellent characteristics, the memory learning and forgetting functions of specific characters and other information can be further simulated.

[0032] (4) The photoelectric synaptic transistor of the present invention also has the advantages of fast and energy-saving preparation process, simple structure, excellent performance, etc., and can be efficiently integrated into a transistor device array of multiple pixel units for applications such as optical imaging and sensor chips. Compared with traditional technologies, the photoelectric synaptic transistor and array of the present invention simplify the manufacturing process, have the characteristics of simple process, low preparation cost, and effective promotion, and can also integrate intrinsically flexible organic semiconductors and dielectric materials and flexible substrates to construct large-area flexible synaptic arrays and integrated devices, learn and forget light pulse signals, and provide new inspiration for the future research and development of ultraviolet light cross-linked dielectric materials and the application of photoelectric detection technology, neuromorphic computing technology, and sensing-storage-computing integrated technology.

[0033] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0035] Figure 1 This is a schematic diagram of the structure of the photosynapse transistor based on ultraviolet light cross-linked dielectric material prepared in Example 1;

[0036] Figure 2 Fourier transform infrared spectrum of the ultraviolet light cross-linked dielectric material used in the photosynaptic transistor prepared in Example 1;

[0037] Figure 3 An atomic force microscope image of the UV-crosslinked dielectric material used in the photosynaptic transistor prepared in Example 1;

[0038] Figure 4 The transfer characteristic curve of the photosynaptic transistor based on the ultraviolet light cross-linked dielectric material prepared in Example 1 under bright and dark states;

[0039] Figure 5 (a) is the output characteristic curve of the photosynaptic transistor based on the UV-crosslinked dielectric material prepared in Example 1 in the dark state;

[0040] Figure 5 (b) is the output characteristic curve of the photosynaptic transistor based on the UV-crosslinked dielectric material prepared in Example 1 under light illumination;

[0041] Figure 6 (a) shows the double pulse facilitation behavior of the photosynaptic transistor based on the UV-crosslinked dielectric material prepared in Example 1;

[0042] Figure 6 (b) is the double pulse facilitation index characteristic of the photosynaptic transistor based on the UV-crosslinked dielectric material prepared in Example 1;

[0043] Figure 7 The light pulse number dependence and short-term memory and long-term memory transition of the photosynaptic transistor based on UV-crosslinked dielectric material prepared in Example 1;

[0044] Figure 8 The transfer characteristic curves of the photosynaptic transistor based on the UV-crosslinked dielectric material prepared in Example 1 in the flat and bent states;

[0045] Fig. 9 The excitatory postsynaptic current behavior of the photosynaptic transistor based on the UV-crosslinked dielectric material prepared in Example 1 in the flat and bent states;

[0046] Fig.10 This is a test schematic diagram of the photosynapse transistor array based on ultraviolet light-crosslinked dielectric materials prepared in Example 17, and a mapping image of the current changes at each pixel in the array under different pulse numbers and different pulse end times.

[0047] Reference numerals: 1 - substrate; 2 - gate; 3 - dielectric layer; 4 - semiconductor layer; 5 - source; 6 - drain. DETAILED DESCRIPTION

[0048] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0049] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0050] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0051] The UV-crosslinked dielectric material used in the following examples is a polymer dielectric material (c-DPHA) having polar hydroxyl functional groups;

[0052] The DPHA monomer structure used in this material is

[0053] If no specific conditions are specified in the following examples, the reaction is carried out under conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the raw materials and solvents in the examples of the present invention can be obtained through public channels, among which:

[0054] Chlorobenzene solvent and methanol solvent were purchased from Sigma-Aldrich (Shanghai) Trading Co., Ltd.;

[0055] The organic polymer semiconductor material indazone-dithiophene-benzothiadiazole copolymer (PIDT-BT) was purchased from Shenzhen Ruixun Optoelectronic Material Technology Co., Ltd.;

[0056] Pentaerythritol penta / hexaacrylate monomer DPHA and photoinitiator Irgacure 184 were purchased from Sigma-Aldrich (Shanghai) Trading Co., Ltd.

[0057] Example 1

[0058] This embodiment provides a photosynaptic transistor based on room temperature solution processing ultraviolet light cross-linked dielectric material, the structure of which is as follows: Figure 1 As shown, from bottom to top, it includes a substrate 1, a gate 2, a dielectric layer 3, and a semiconductor layer 4. A source electrode 5 and a drain electrode 6 having a channel pattern are respectively located on the surfaces of both ends of the semiconductor layer 4.

[0059] The preparation method of the photosynaptic transistor is as follows:

[0060] (1) A polyethylene terephthalate (125 μm thick, serving as a substrate) having an indium tin oxide conductive film coating (serving as a gate) was subjected to UV-ozone treatment for 15 min;

[0061] (2) On the surface of the substrate / gate, a methanol solution containing 40 wt.% DPHA and 2 wt.% photoinitiator is spin-coated onto the surface of the substrate / gate in step (1) (wherein the spin-coating speed is 3000 rpm and the spin-coating time is 30 s). After the spin-coating, the solution is cross-linked under 365 nm ultraviolet light for 10 min to form a dielectric layer.

[0062] (3) In a glove box with a nitrogen atmosphere, a chlorobenzene solution of PIDT-BT with a concentration of 5 mg / mL is spin-coated onto the dielectric layer obtained in step (2) (wherein the spin-coating speed is 2000 rpm and the spin-coating time is 60 s), followed by annealing on a heating table at 80° C. for 20 min to form a semiconductor layer;

[0063] (4) On the surface of the semiconductor layer, a vacuum thermal evaporation process (vacuum degree of about 2×10 - 4 Pa, evaporation rate is about ) Prepare 50nm thick gold as the source and drain respectively, wherein there is a channel with a width and a length of 22.5mm and 0.15mm respectively between the prepared source and drain, and the photoelectric synapse transistor of the ultraviolet light cross-linked dielectric material can be prepared.

[0064] Embodiments 2 to 16

[0065] The differences between the preparation process of the photosynaptic transistor based on the UV-crosslinked dielectric material in Examples 2 to 16 and Example 1 are shown in Table 1, and the parts not explained are the same as in Example 1.

[0066] Table 1

[0067]

[0068] Embodiment 17

[0069] In order to better utilize the light pulse response capability of the photosynaptic transistor described in Example 1, a 10×10 array of photosynaptic transistors based on room temperature solution processed ultraviolet light cross-linked dielectric materials was designed and prepared, and visual imaging research on light pulse memory learning and forgetting processes was carried out. The specific preparation method of the synaptic transistor array is as follows:

[0070] (1) Using 125 μm thick polyethylene terephthalate as the substrate;

[0071] (2) On the surface of the above substrate, a vacuum thermal evaporation process (vacuum degree is about 2×10 -4 Pa, evaporation rate is about ) Prepare 10 50 nm thick gold strips as gates of a 10×10 array;

[0072] (3) On the surface of the substrate / gate, a methanol solution of 40 wt.% DPHA and 2 wt.% photoinitiator is spin-coated onto the substrate with the gate prepared in step (2) (wherein the rotation speed during the spin coating process is 3000 rpm and the spin coating time is 30 s). After the spin coating is completed, the dielectric layer c-DPHA with a cross-linked network structure is prepared by cross-linking with ultraviolet light at a wavelength of 365 nm for 10 min;

[0073] (4) In a glove box with a nitrogen atmosphere, a chlorobenzene solution of PIDT-BT with a concentration of 5 mg / mL was spin-coated onto the dielectric layer obtained in step (3) (wherein the spin-coating speed was 2000 rpm and the spin-coating time was 60 s), and then annealed on a heating table at 80° C. for 20 min to form a semiconductor layer;

[0074] (5) On the semiconductor layer, a vacuum thermal evaporation process (vacuum degree of about 2×10 - 4 Pa, evaporation rate is about ) Prepare 50nm thick gold as the source and drain of a 10×10 array, where the width and length of the channel between the source and the drain are 3.75mm and 0.15mm respectively, and the channel parts formed between the 10 sources and drains cover the gate respectively, and the photoelectric synapse transistor array based on UV-crosslinked dielectric materials can be prepared.

[0075] Performance Testing

[0076] 1. Perform Fourier transform infrared spectroscopy and surface morphology testing on UV-crosslinked dielectric materials

[0077] Nicolet iS5 spectrophotometer was used to perform Fourier transform infrared spectroscopy on the ultraviolet cross-linked dielectric material c-DPHA used in preparing the photosynaptic transistor in Example 1. The test results are as follows: Figure 2 As shown. It can be seen that this type of UV-crosslinked dielectric material has hydroxyl polar functional groups, indicating that the use of UV-crosslinked dielectric material c-DPHA as a dielectric layer can generate interface traps between the organic semiconductor layer, regulate the separation and recombination of photogenerated carriers, and realize photosynaptic transistors.

[0078] The surface morphology of the dielectric film of the ultraviolet cross-linked dielectric material c-DPHA used in preparing the photosynaptic transistor in Example 1 was measured using an atomic force microscope (Bruker Dimension ICON). The test results are as follows: Figure 3 As shown. It can be seen that the root mean square roughness of the surface of the c-DPHA dielectric layer is very small (about 0.48nm), indicating that this type of UV-crosslinked organic dielectric material has high quality and can meet the subsequent device application requirements.

[0079] 2. Performance testing of photosynaptic transistors based on UV-crosslinked dielectric materials

[0080] The electrical performance of the photoelectric synaptic transistor based on the UV-crosslinked dielectric material c-DPHA prepared in Example 1 was tested under light and dark conditions using a MZLASER with a wavelength of 685 nm and an Agilent 4155C semiconductor parameter analyzer. The transfer characteristic curve is shown in FIG. Figure 4 In addition, the output characteristic curves of the photosynaptic transistor in the dark state and in the light state are shown in Figure 5 (a) and Figure 5 (b) As shown in the electrical performance test results of the photosynaptic transistor, it can be seen that the photosynaptic transistor based on the ultraviolet light cross-linked dielectric material c-DPHA proposed in the present invention has good transistor characteristics and light response characteristics.

[0081] The synaptic behavior test of the photosynaptic transistor based on the UV-crosslinked dielectric material c-DPHA prepared in Example 1 was carried out using a MZLASER with a wavelength of 685 nm and an Agilent 4155C semiconductor parameter analyzer (pulse width of 600 ms and pulse interval of 90 ms). The double-pulse facilitation behavior and double-pulse facilitation index characteristics are shown in Figures 1 and 2. Figure 6 (a) and Figure 6(b) As shown. It can be seen that the photosynaptic transistor proposed in the present invention has efficient PPF synaptic response characteristics. In particular, as the light pulse interval increases, the double pulse facilitation index shows a gradual downward trend. The relaxation times of the fast decline zone and the slow decline zone can be well fitted by the double exponential function to be approximately 75.6ms and 1310.5ms, respectively, which are comparable to the relaxation time scale of biological synapses.

[0082] The light pulse number dependence behavior of the photosynaptic transistor based on the UV-crosslinked dielectric material c-DPHA prepared in Example 1 was tested using a MZLASER with a wavelength of 685 nm and an Agilent 4155C semiconductor parameter analyzer (pulse width of 600 ms and pulse interval of 90 ms). The test results are shown in FIG. Figure 7 It can be seen that the photosynaptic transistor proposed in the present invention realizes the transformation from short-term memory to long-term memory and successfully simulates the memory characteristics of biological synapses.

[0083] The bending characteristics of the photosynaptic transistor based on the UV-crosslinked dielectric material c-DPHA prepared in Example 1 were tested using a MZLASER with a wavelength of 685 nm and an Agilent 4155C semiconductor parameter analyzer (the pulse width and pulse interval were both 90 ms). Figure 8 and Fig. 9 It can be seen that the photosynaptic transistor proposed in the present invention still maintains the transfer characteristic curve and the excitatory postsynaptic current performance basically unchanged when the bending radius is 17 mm, showing good bending stability.

[0084] Similarly, the performance of the photosynaptic transistor based on the ultraviolet light cross-linked dielectric material c-DPHA prepared in other embodiments was tested using a MZLASER laser with a wavelength of 685 nm in combination with an Agilent 4155C semiconductor parameter analyzer. The test results were similar to the performance of the photosynaptic transistor based on the ultraviolet light cross-linked dielectric material c-DPHA prepared in Example 1, indicating that the photosynaptic transistor based on the ultraviolet light cross-linked dielectric material c-DPHA prepared by the method of the present invention can also achieve efficient synaptic response to light pulses, and has good potential application prospects in the future research on ultraviolet light cross-linked dielectric materials and artificial photoelectric synapse technology.

[0085] 3. Performance testing of photosynaptic transistor arrays based on UV-crosslinked dielectric materials

[0086] First, an "OK"-shaped mask was introduced in front of the photosynaptic transistor array based on ultraviolet light cross-linked dielectric materials prepared in Example 17 to block it; then, 30 light pulses (685nm) were stimulated to the patterned shielded transistor array (pulse width was 600ms, pulse interval was 90ms), and the current changes of each device unit (pixel) in the transistor array before and after the pulse were recorded. Among them, the number of pulses can represent the number of learning iterations of the brain, and the time after the pulse corresponds to the forgetting time. Fig.10 As shown, the photosynaptic transistor array exhibits the characteristics of fast learning and slow forgetting, effectively simulating the dynamic learning and forgetting process of the human brain. At the same time, the slight color difference between different pixels shows that this type of OFET-type photosynaptic array has a high degree of uniformity and reliability. These results show the good potential of photosynaptic transistor arrays based on UV-crosslinked dielectric materials in practical applications.

[0087] In summary, the present invention discloses a photoelectric synaptic transistor based on room temperature solution processing ultraviolet light cross-linked dielectric materials, which mainly adopts ultraviolet light cross-linked dielectric material c-DPHA (whose monomer DPHA structural formula is ) as a dielectric layer for preparing photosynaptic transistors, and successfully developed organic photosynaptic transistors and arrays with efficient synaptic response. The photosynaptic transistor proposed in the present invention can make full use of the photogenerated carrier capture ability of hydroxyl groups to achieve the current gain effect under continuous pulses; at the same time, the photosynaptic transistor can realize the photosynaptic device to imitate the biological synaptic function by modulating the light pulse signal to meet the application needs of information learning and memory functional photosynapses. Compared with traditional technologies, the photosynaptic transistor proposed in the present invention simplifies the manufacturing process and reduces costs. It has the advantages of low energy consumption, simple structure, and excellent performance. It can be further efficiently integrated into multi-pixel transistor arrays and large-area flexible synaptic arrays to learn and forget light pulses, providing useful ideas for the future research on ultraviolet light-crosslinked dielectric materials and the potential applications of photoelectric detection, optical imaging, smart terminals, sensor chips, artificial synapses, neuromorphic computing, and sensing, storage, and computing integration.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A photosynaptic transistor, characterized in that: The dielectric material of the photosynaptic transistor is a room temperature solution processed UV cross-linked dielectric material; The ultraviolet light cross-linked dielectric material is an organic polymer dielectric material c-DPHA having a hydroxyl polar functional group, wherein the DPHA monomer structure of the polymer dielectric material is 2. The photosynaptic transistor according to claim 1, characterized in that The photosynaptic transistor comprises, from bottom to top, a substrate (1), a gate (2), a dielectric layer (3), a semiconductor layer (4), and a source electrode (5) and a drain electrode (6) at the top; A conductive channel with a micro-nano scale spacing is formed between the source electrode (5) and the drain electrode (6).

3. The photosynaptic transistor according to claim 2, characterized in that The material of the substrate (1) is any one or more of polyethylene naphthalate, polyethylene terephthalate, polyimide, polydimethylsiloxane, polycarbonate, polyvinyl alcohol, glass, silicon dioxide / silicon or sapphire.

4. The photosynaptic transistor according to claim 2, characterized in that The material of the gate electrode (2), source electrode (5) or drain electrode (6) is any one or more of gold, silver, aluminum, copper, chromium, platinum, titanium, nickel, indium tin oxide, fluorine-doped tin oxide, zinc aluminum oxide or conductive polymer.

5. The photosynaptic transistor according to claim 4, characterized in that The conductive polymer has a conjugated main electron system on its main chain, including a polymer material or a small molecule material that achieves a conductive state by doping; the conductive polymer includes any one of polyaniline, polythiophene, polyacetylene, and 2,7-dioctyl[1]benzothiophene[3,2-b][1]benzothiophene.

6. The photosynaptic transistor according to claim 2, characterized in that: The material of the semiconductor layer (4) is a conjugated polymer semiconductor material or an organic small molecule semiconductor material; The conjugated polymer semiconductor material includes any one or more of poly 3-hexylthiophene or its derivatives, indacendithiophene-benzothiadiazole copolymer, 7,7,8,8-tetracyanoquinodimethane-doped indacendithiophene-benzothiadiazole copolymer, poly {4,8-bis [(2-ethylhexyl)oxy]benzo [1,2-b:4,5-b'] disulfide-2,6-diyl} {3-fluoro-2- [(2-ethylhexyl)carbonyl]thieno [3,4-b]thiophene diyl} or its derivatives, and copolymers of terthiophene and perylene imide units; The organic small molecule semiconductor material includes any one or more of pentacene or its derivatives, 7,7,8,8-tetracyanoquinodimethane or its derivatives, and copper phthalocyanine.

7. A photosynaptic transistor array, characterized in that: The photosynaptic transistor array comprises a plurality of photosynaptic transistors according to any one of claims 1 to 6 arranged in an array; The photosynapse transistor array is configured with at least four pairs of source electrodes (5) and drain electrodes (6).

8. The method for preparing a photosynaptic transistor according to any one of claims 1 to 6, characterized in that: The method includes: (1) obtaining a phototransistor substrate, and forming a gate on the surface of the substrate; (2) on the surface of the gate and the substrate, a dielectric layer based on a room temperature solution processed ultraviolet light cross-linked dielectric material is formed by any one of spin coating, blade coating or inkjet printing and cross-linked by room temperature photocuring; (3) forming a semiconductor layer on the surface of the dielectric layer; (4) A source electrode and a drain electrode are formed on the surface of the semiconductor layer, and a conductive channel with a micro-nano scale spacing is formed between the source electrode and the drain electrode, thereby obtaining a photosynaptic transistor.

9. The preparation method according to claim 8, characterized in that: The dielectric layer is prepared on the surface of the gate and the substrate by a spin coating method; in the solution used in the spin coating process, the mass fraction of the dielectric layer material is 10-50wt.%, the mass fraction of the ultraviolet light initiator is 1-5wt.%, the solvent is any one or more of methanol, ethanol or isopropanol, the spin coating speed is 500-4000rpm, and the spin coating time is 30-90s; after spin coating, the time for 365nm wavelength ultraviolet light crosslinking is 2-30min, and the environment of the ultraviolet light crosslinking is room temperature atmospheric environment.

10. Application of the photosynaptic transistor according to any one of claims 1 to 6 or the photosynaptic transistor array according to claim 7 in the field of photoelectric detection and imaging, smart terminals, sensor chips, neuromorphic computing or sensing, storage and computing integrated technology.

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