An organic synaptic device with high polarization sensitivity and preparation method thereof

Abstract

This invention discloses an organic synaptic device with high polarization sensitivity and a method for its preparation, belonging to the fields of optoelectronic materials and neuromorphic computing. The device comprises, from bottom to top, a first solid-phase substrate, a capture layer, and an active layer. The active layer comprises a first and second two-dimensional organic molecular crystal films, both in contact with the capture layer. The second two-dimensional organic molecular crystal film partially overlies the first two-dimensional organic molecular crystal film to form a type II bandgap heterojunction. A first electrode is disposed on the surface of the first two-dimensional organic molecular crystal film, and a second electrode is disposed on the second two-dimensional organic molecular crystal film. This device successfully overcomes the intrinsic anisotropy limitations of two-dimensional semiconductor materials, significantly reducing device noise while significantly enhancing both light response intensity and polarization detection capabilities.

Description

Technical Field

[0001] The present invention relates to an organic synaptic device with high polarization sensitivity and a preparation method thereof, belonging to the technical field of optoelectronic materials and neuromorphic computing. Background Art

[0002] Polarization imaging technology, by analyzing the polarization of light, provides a new visual dimension for intelligent agents' perception and decision-making in complex environments, significantly improving their adaptability in dynamic scenes. Inspired by biological visual systems, polarization-sensitive artificial synapses, integrating sensing, storage, and computing, demonstrate enormous potential for biomimetic vision. This technology not only effectively overcomes the performance bottlenecks of traditional von Neumann architectures but also offers a novel solution for high-performance computing, thus driving a significant leap forward in polarization imaging technology.

[0003] Traditional polarization-sensitive devices are mostly based on inorganic materials. However, their inherent limitations (high manufacturing costs, poor compatibility with flexible substrates, and complex micro-nanofabrication processes) severely restrict their practical application in flexible electronics and miniaturized intelligent integrated devices. Two-dimensional organic molecular crystals, due to their unique intrinsic anisotropy and excellent photoelectric response properties, combined with their light-induced minority carrier capture mechanism, have become ideal candidates for a new generation of miniaturized, on-chip integrated linearly polarized light-responsive artificial intelligence sensing systems, opening up broad prospects for the future development of intelligent sensing technologies.

[0004] However, despite the significant advantages of two-dimensional organic molecular crystals in synaptic linear polarization recognition, their intrinsic anisotropy still limits further improvements in the dichroic ratio, making it difficult to meet the high sensitivity requirements of practical applications. Therefore, exploring new strategies to overcome the limitations of intrinsic material anisotropy and further improve the linear polarization sensitivity of optoelectronic synaptic devices has become a key research direction. Summary of the Invention

[0005] In order to overcome the shortcomings of the existing technology, the present invention provides an organic synaptic device with high polarization sensitivity and a preparation method thereof, which can break through the intrinsic anisotropy limitation of two-dimensional semiconductor materials and achieve high polarization sensitivity.

[0006] The technical solution adopted by the present invention to solve its technical problem is:

[0007] In a first aspect, the present application provides a method for preparing an organic synaptic device with high polarization sensitivity, comprising the following steps:

[0008] preparing a capture layer on a first solid substrate;

[0009] preparing a first two-dimensional organic molecular crystal film with a smaller area than the capture layer on a first liquid phase substrate, and preparing a second two-dimensional organic molecular crystal film with a smaller area than the capture layer on a second liquid phase substrate;

[0010] transferring the first two-dimensional organic molecular crystal film onto the capture layer;

[0011] Transferring the second two-dimensional organic molecular crystal film onto the capture layer so that the first two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film intersect in shape and form a type II energy band heterojunction;

[0012] Electrodes are prepared on the surfaces of the first two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film respectively to obtain the organic synapse device with high polarization sensitivity.

[0013] The device produced by the method for preparing an organic synaptic device with high polarization sensitivity provided in this application successfully breaks through the intrinsic anisotropy limitation of two-dimensional semiconductor materials, not only significantly reduces device noise, but also greatly enhances the light response intensity and polarization detection capability.

[0014] In order to achieve a structure in which both the first two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film are in contact with the capture layer, and the second two-dimensional organic molecular crystal film is partially superimposed on the first two-dimensional organic molecular crystal film, the area of the first two-dimensional organic molecular crystal film prepared on the first liquid phase substrate in this application is smaller than the capture layer. This allows the first two-dimensional organic molecular crystal film to be in contact with the capture layer by simply lifting it up from the contact surface, and there are exposed locations on the capture layer ready to be in contact with the second two-dimensional organic molecular crystal film. However, if the operation of transferring the second two-dimensional organic molecular crystal film to the capture layer is also a simple lifting operation, the randomness is relatively large and it is difficult to align with the naked eye at the micro-nano scale (device size). In this case, the second two-dimensional organic molecular crystal film is difficult to adhere to the ideal position. After the second two-dimensional organic molecular crystal film adheres to the first solid phase substrate, the size or shape of the location on the surface of the first two-dimensional organic molecular crystal film where the electrode can be arranged may also be undesirable.

[0015] Preferably, the step of transferring the second two-dimensional organic molecular crystal film onto the capture layer so that the first two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film intersect in shape and form a type II energy band heterojunction comprises:

[0016] contacting the second liquid substrate with a second solid substrate having a UV anti-viscosity film on one side so that the second two-dimensional organic molecular crystal film adheres to the UV anti-viscosity film, and lifting and drying the second solid substrate;

[0017] The first solid substrate is brought into contact with the second solid substrate so that the first two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film face each other, so that the first two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film intersect and form a type II energy band heterojunction;

[0018] The UV anti-viscosity film is irradiated with ultraviolet light to make it lose its viscosity, and the second solid phase substrate is peeled off.

[0019] This application first uses a second solid-phase substrate with a UV anti-viscosity film to contact and lift the second two-dimensional organic molecular crystal film. After that, the relative positions of the first solid-phase substrate and the second solid substrate can be easily adjusted, and the second two-dimensional organic molecular crystal film can be easily arranged at an ideal position on the first solid-phase substrate, fully contacting with the capture layer and the first two-dimensional organic molecular crystal film, and ensuring that the size and shape of the position where the first two-dimensional organic molecular crystal film is still exposed are suitable for arranging one of the electrodes (the first electrode below).

[0020] More preferably, the step of bringing the first solid substrate into contact with the second solid substrate so that the first two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film face to face, so that the first two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film intersect in shape and form a type II band heterojunction, comprises:

[0021] placing the first solid substrate on a platform with the first two-dimensional organic molecular crystal film facing upward;

[0022] Fixing the transparent second solid substrate in suspension on a cantilever with the second two-dimensional organic molecular crystal film facing downward;

[0023] Adjusting the cantilever so that the vertical projection of the second two-dimensional organic molecular crystal film is within the range of the capture layer, and the vertical projection of the second two-dimensional organic molecular crystal film intersects with the shape of the first two-dimensional organic molecular crystal film;

[0024] The cantilever is lowered until the first two-dimensional organic molecular crystal film contacts the second two-dimensional organic molecular crystal film.

[0025] The transparent second solid-phase substrate can be, for example, a glass plate, which is advantageous for vertically observing the position of the second two-dimensional organic molecular crystal film relative to the first two-dimensional organic molecular crystal film and the capture layer under a microscope when the second solid-phase substrate is suspended in the air. After alignment, the second solid-phase substrate is lowered to allow the second two-dimensional organic molecular crystal film to adhere to the first two-dimensional organic molecular crystal film and the capture layer.

[0026] Optionally, the UV anti-viscosity film is selected from one of Lion 6360-15, Lion 6360-20, Lion 6360-25, and Lion 6360-95;

[0027] In the step of irradiating the UV anti-viscosity film with ultraviolet light to make it lose its viscosity, the wavelength of the light is 365nm and the intensity of the light is 1mW / cm 2 ~50 mW / cm 2 , the irradiation time is 10s~30s.

[0028] Selecting a specific UV adhesive film and strictly controlling the illumination parameters ensures that it performs optimally during the crystal film transfer process. A suitable adhesive film not only ensures the crystal film adheres well during transfer, but also allows for smooth detackification and subsequent peeling through illumination, preventing damage to the 2D organic molecular crystal film and the heterojunction. This consistently improves heterojunction fabrication quality and optimizes the device's polarization sensitivity.

[0029] Preferably, the UV anti-viscosity film is Lion 6360-15;

[0030] In the step of irradiating the UV anti-viscosity film with ultraviolet light to make it lose its viscosity, the light intensity is 10 mW / cm 2 , the irradiation time is 30s.

[0031] This specific combination of materials and lighting parameters can achieve the best transfer effect, minimize errors in the preparation process, and help improve the stability of the device.

[0032] Optionally, before the step of preparing electrodes on the surfaces of the first two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film, the method further comprises the following steps:

[0033] forming a third two-dimensional organic molecular crystal film having an area smaller than that of the first two-dimensional organic molecular crystal film on a third liquid substrate;

[0034] transferring the third two-dimensional organic molecular crystal film to the first solid substrate so that a portion of the third two-dimensional organic molecular crystal film overlaps the second two-dimensional organic molecular crystal film and a remaining portion overlaps the first two-dimensional organic molecular crystal film, so that the third two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film form another type II band heterojunction;

[0035] The electrodes include a second electrode in contact with the second two-dimensional organic molecular crystal film, and a first electrode in contact with both the first two-dimensional organic molecular crystal film and the third two-dimensional organic molecular crystal film.

[0036] The active layer of the device prepared in this way has three layers, and the presence of two parallel heterojunctions can completely deplete the middle absorption layer, with higher polarization sensitivity than that of a double-layer two-dimensional organic molecular crystal film.

[0037] In a second aspect, the present application provides an organic synapse device with high polarization sensitivity, which includes, from bottom to top, a first solid substrate, a capture layer and an active layer, the active layer including a first two-dimensional organic molecular crystal film and a second two-dimensional organic molecular crystal film both in contact with the capture layer, the second two-dimensional organic molecular crystal film is partially superimposed on the first two-dimensional organic molecular crystal film to form a type II band heterojunction, a first electrode is provided on the surface of the first two-dimensional organic molecular crystal film, and a second electrode is provided on the second two-dimensional organic molecular crystal film.

[0038] This device is a high-performance, strongly polarization-sensitive optoelectronic synaptic device based on heterogeneous integration of two-dimensional organic molecular crystals. Through the coordinated setting of highly crystalline two-dimensional organic molecular crystals and type II bandgap heterojunctions, it can effectively regulate polarization-dependent charge transport, achieving high polarization sensitivity and optoelectronic synaptic functions. This device is suitable for intelligent polarization imaging, dynamic target tracking, and light-controlled neuromorphic computing systems, solving the problem of insufficient sensitivity of traditional devices due to limited intrinsic anisotropy.

[0039] Furthermore, the organic synapse device with high polarization sensitivity has a linear polarization dichroism ratio of ≥10.

[0040] The high linear polarization dichroic ratio indicates that the device has extremely high sensitivity in polarized light detection, and can accurately distinguish light signals with different polarization directions. This breaks through the limitations of the material's intrinsic anisotropy and significantly improves the performance of polarization-based visual imaging and light-controlled neuromorphic computing systems, making them suitable for high-end applications requiring extremely high polarization sensitivity.

[0041] Furthermore, the thickness of the first two-dimensional organic molecular crystal film is 1nm~100nm, the thickness of the second two-dimensional organic molecular crystal film is 1nm~100nm, the thickness of the capture layer is 5nm~15nm, the thickness of the first electrode is 10nm~100nm, and the thickness of the second electrode is 10nm~100nm.

[0042] Appropriate film thickness fully exploits the material's properties, optimizes contact with the electrodes, and facilitates charge injection and transport. These factors work together to enhance the device's overall performance, ensuring the stable realization of high polarization sensitivity and enhancing device reliability during operation.

[0043] Furthermore, the active layer also includes a third two-dimensional organic molecular crystal film, which is partially stacked on the second two-dimensional organic molecular crystal film, and the remaining portion is stacked on the first two-dimensional organic molecular crystal film, and the third two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film form another type II band heterojunction; the first electrode is in contact with both the first two-dimensional organic molecular crystal film and the third two-dimensional organic molecular crystal film.

[0044] The beneficial effects of the present invention are as follows: By utilizing a heterojunction structure with a type II band alignment and combining it with the high crystallinity of a two-dimensional organic molecular crystal, the device produced by the present invention significantly improves the separation efficiency and transmission speed of photogenerated carriers, while effectively suppressing the generation of dark current. Furthermore, the built-in electric field induced in the heterojunction precisely regulates the polarization-dependent charge transport within the conductive channel, thereby significantly amplifying the anisotropic photocurrent. Ultimately, this device achieves breakthrough progress in terms of high polarization sensitivity and superior photoelectric response characteristics, providing a reliable technical path for the development of high-performance polarization-sensitive neuromorphic devices.

[0045] Other features and advantages of the present application will be described in the following description, and in part will become apparent from the description, or understood by practicing the present application. The purpose and other advantages of the present application can be realized and obtained by the structures particularly pointed out in the written description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is one of the structural schematic diagrams of an organic synaptic device with high polarization sensitivity provided in an embodiment of the present application.

[0047] Figure 2 This is the second structural schematic diagram of an organic synaptic device with high polarization sensitivity provided in an embodiment of the present application.

[0048] Figure 3 This is a flow chart of a method for preparing an organic synaptic device with high polarization sensitivity provided in an embodiment of the present application.

[0049] Figure 4 Schematic diagram of the type II band arrangement of the DTT-8 / TFT-CN heterojunction.

[0050] Figure 5 is an optical microscope image of the heterojunction prepared in the implementation case.

[0051] Figure 6 This is the polarization synapse performance test result of the device produced in the implementation case.

[0052] Figure numerals: 1. first solid substrate; 2. capture layer; 3. active layer; 31. first two-dimensional organic molecular crystal film; 32. second two-dimensional organic molecular crystal film; 33. third two-dimensional organic molecular crystal film; 41. first electrode; 42. second electrode; 5. second solid substrate. DETAILED DESCRIPTION

[0053] To make the purpose, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure are clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] It should be understood that, under the premise of no conflict, any and all embodiments of the present invention can be combined with the technical features in any other embodiment or multiple other embodiments to obtain additional embodiments. The present invention includes such combinations to obtain additional embodiments.

[0055] Unless otherwise specified, all technical and scientific terms used herein have the standard meanings in the art to which the claimed subject matter belongs. If there are multiple definitions for a term, the definition herein shall prevail.

[0056] Reference Figure 1 An embodiment of the present application provides an organic synaptic device with high polarization sensitivity, which includes, from bottom to top, a first solid substrate 1, a capture layer 2 and an active layer. The active layer includes a first two-dimensional organic molecular crystal film 31 and a second two-dimensional organic molecular crystal film 32, both of which are in contact with the capture layer 2. The second two-dimensional organic molecular crystal film 32 is partially superimposed on the first two-dimensional organic molecular crystal film 31 to form a type II band heterojunction. A first electrode 41 is provided on the surface of the first two-dimensional organic molecular crystal film, and a second electrode 42 is provided on the second two-dimensional organic molecular crystal film.

[0057] The device regulates the polarization-dependent charge transfer path through the synergistic effect of the built-in electric field of the heterojunction and the intrinsic anisotropy of the organic single crystal material, thereby achieving optoelectronic synaptic function with high polarization sensitivity and zero power consumption.

[0058] The material of the electrodes (including the first electrode and the second electrode) can be gold, silver, copper, etc. The electrodes are located at both ends of the heterojunction layer to form a source electrode and a drain electrode.

[0059] The material of the capture layer can be PMMA (polymethyl methacrylate), PS (polystyrene), PVN (poly(2-vinylnaphthalene)), PVA (polyvinyl alcohol) or PVP (poly(4-vinylphenol)).

[0060] The first solid substrate may be a silicon wafer, silicon dioxide, or PET (polyethylene terephthalate), etc.

[0061] The thickness of the first two-dimensional organic molecular crystal film is 1nm~100nm, the thickness of the second two-dimensional organic molecular crystal film is 1nm~100nm, the thickness of the capture layer is 5nm~15nm, the thickness of the first electrode is 10nm~100nm, and the thickness of the second electrode is 10nm~100nm.

[0062] The two-dimensional organic molecular crystal is selected from TFT-CN, DTT-8, C6-DPA, C8-BTBT, C12-BTBT, and TIPS-PEN. When the first two-dimensional organic molecular crystal film is TFT-CN, the second two-dimensional organic molecular crystal film is selected from one of DTT-8, C6-DPA, C8-BTBT, C12-BTBT, and TIPS-PEN; when the first two-dimensional organic molecular crystal film is selected from one of DTT-8, C6-DPA, C8-BTBT, C12-BTBT, and TIPS-PEN, the second two-dimensional organic molecular crystal film is TFT-CN.

[0063] The type II band arrangement of the heterojunction significantly improves the efficiency of photogenerated carrier separation, suppresses dark current, and drives anisotropic charge transport through the built-in electric field, making the linear polarization dichroic ratio break through to ≥10.

[0064] In some embodiments, the first two-dimensional organic molecular crystal film is DDT-8, the second two-dimensional organic molecular crystal film is TFT-CN, the first electrode is gold, and the second electrode is silver.

[0065] The present application accordingly provides a method for preparing the device, the steps comprising:

[0066] S1: preparing a capture layer on a first solid substrate.

[0067] S2: preparing a first two-dimensional organic molecular crystal film with an area smaller than the capture layer on the first liquid phase substrate, and preparing a second two-dimensional organic molecular crystal film with an area smaller than the capture layer on the second liquid phase substrate.

[0068] S3: transferring the first two-dimensional organic molecular crystal film onto the capture layer.

[0069] S4: transferring the second two-dimensional organic molecular crystal film onto the capture layer so that the first two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film intersect in shape and form a type II energy band heterojunction.

[0070] S6: Electrodes are prepared on the surfaces of the first two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film, respectively, to obtain an organic synaptic device with high polarization sensitivity.

[0071] Step S1 may specifically be to spin-coat the capture layer thin film on the surface of the first solid substrate using a spin coating method.

[0072] The specific steps of step S2 are as follows:

[0073] A first organic semiconductor solution is dripped onto the first liquid phase substrate, and the first organic semiconductor solution spreads into a continuous liquid film on the first liquid phase substrate; a second organic semiconductor solution is dripped onto the second liquid phase substrate, and the second organic semiconductor solution spreads into a continuous liquid film on the second liquid phase substrate.

[0074] After the volatile organic solvent is completely evaporated, a uniform two-dimensional organic molecular crystal is formed on the surface of the liquid phase substrate, that is, a first two-dimensional organic molecular crystal film is obtained on the surface of the first liquid phase substrate, and a second two-dimensional organic molecular crystal film is obtained on the surface of the second liquid phase substrate.

[0075] The solute of the first organic semiconductor solution is, for example, one of DTT-8, C6-DPA, C8-BTBT, C12-BTBT, and TIPS-PEN, and the solute of the second organic semiconductor solution is, for example, TFT-CN. Alternatively, the solute of the second organic semiconductor solution is one of DTT-8, C6-DPA, C8-BTBT, C12-BTBT, and TIPS-PEN, and the solute of the first organic semiconductor solution is, for example, TFT-CN.

[0076] The solvents of the first organic semiconductor solution and the second organic semiconductor solution can be independently toluene, chlorobenzene or o-dichlorobenzene, so as to ensure that the solutions can evaporate slowly after being added dropwise to form a uniform single crystal thin film.

[0077] The first liquid phase substrate and the second liquid phase substrate can independently be water, glycerol or a mixture thereof. By introducing the liquid phase substrate, the coffee ring effect can be effectively suppressed, thereby obtaining a two-dimensional organic molecular crystal with uniform and controllable thickness.

[0078] The concentration ranges of the first organic semiconductor solution and the second organic semiconductor solution are independently 0.01 mg / mL to 8 mg / mL, and can be adjusted according to the thickness and morphology requirements of the target film.

[0079] The amount of organic semiconductor solution added can be precisely controlled based on actual needs. For example, in a 40 mm × 70 mm weighing bottle, the amount added is typically 10 μL to 100 μL. By adjusting the amount added, the thickness of the two-dimensional organic molecular crystal can be precisely controlled, ranging from a monolayer to several hundred nanometers. In this application, the thickness of each two-dimensional organic molecular crystal in the heterojunction is 1 nm to 100 nm.

[0080] The specific steps of step S3 are as follows:

[0081] Align the first solid substrate with the first two-dimensional organic molecular crystal film on the surface of the first liquid substrate and slowly approach it. Use the side with the capture layer to contact the grown two-dimensional organic molecular crystal on the liquid surface. Once the two are in full contact, slowly lift the first solid substrate away from the liquid surface. The two-dimensional organic molecular crystal prepared on the first liquid substrate is then transferred to the first solid substrate. The first solid substrate is then rinsed with deionized water and air-dried to obtain the first two-dimensional organic molecular crystal film on the first solid substrate. Similarly, the second two-dimensional organic molecular crystal film can be lifted up by contacting the first solid substrate to which the first two-dimensional organic molecular crystal film is attached, thereby attaching it to the first solid substrate.

[0082] This application also provides a more optimized device, refer to Figure 2 The active layer also includes a third two-dimensional organic molecular crystal film 33, which is partially stacked on the second two-dimensional organic molecular crystal film 32, and the remaining portion is stacked on the first two-dimensional organic molecular crystal film 31. Before the electrodes are arranged, there is still an exposed portion on the first two-dimensional organic molecular crystal film 31, and the third two-dimensional organic molecular crystal film 33 and the second two-dimensional organic molecular crystal film 32 form another type II energy band heterojunction; the first electrode 41 is in contact with both the first two-dimensional organic molecular crystal film 31 and the third two-dimensional organic molecular crystal film 33.

[0083] Thus, the active layer has three layers, and has higher polarization sensitivity than a two-layer two-dimensional organic molecular crystal film.

[0084] In this device, the thickness of the third two-dimensional organic molecular crystal film 33 is 1 nm to 100 nm, and the thickness requirements of the remaining layers are the same as when the active layer is two layers.

[0085] In this device, the first two-dimensional organic molecular crystal film 31 and the third two-dimensional organic molecular crystal film 33 are both TFT-CN, the second two-dimensional organic molecular crystal film 32 is one of DTT-8, C6-DPA, C8-BTBT, C12-BTBT, TIPS-PEN, the first electrode is silver, and the second electrode is gold.

[0086] Although the contact and lifting operation in the aforementioned step S3 is simple, the position of adhesion of the organic molecular crystal film is relatively random. In order to make the first two-dimensional organic molecular crystal film contact with the capture layer and there are exposed positions on the capture layer ready to contact with the second two-dimensional organic molecular crystal film, this application stipulates that the area of the first two-dimensional organic molecular crystal film is smaller than the capture layer. This can be achieved by adjusting the volume of the first organic semiconductor solution.

[0087] However, when it is necessary to arrange the second two-dimensional organic molecular crystal film according to a preset structure, or even to arrange a third two-dimensional organic molecular crystal film, if two or even three layers are lifted by contact, the randomness is too great. Simply controlling the area of the two-dimensional organic molecular crystal film to be smaller than the capture layer is still not easy to make the second two-dimensional organic molecular crystal film and the third two-dimensional organic molecular crystal film adhere to the ideal position on the first solid substrate, especially at the micro-nano device scale.

[0088] This application proposes a better transfer operation for this purpose, referring to Figure 3 , taking the preparation of the active layer 3 containing two layers of two-dimensional organic molecular crystal films as an example.

[0089] First, if Figure 3 In the first row, the first solid substrate 1 is placed close to the first two-dimensional organic molecular crystal film on the liquid surface of the first liquid substrate, with a capture layer (to avoid the layers being too complicated, Figure 3 The capture layer is not drawn in the figure. One side of the first solid substrate contacts the two-dimensional organic molecular crystal grown on the liquid surface. When the two are fully in contact, the first solid substrate is lifted away from the liquid surface. The two-dimensional organic molecular crystal prepared on the first liquid substrate is transferred to the first solid substrate. The first solid substrate is then rinsed with deionized water and air-dried to obtain a first two-dimensional organic molecular crystal film 31 on the first solid substrate.

[0090] Then, if Figure 3 The second row will have UV anti-sticking film (to avoid the layers being too complicated, Figure 3 The second solid substrate 5 (the UV anti-viscosity film is not shown) slowly approaches and contacts the second two-dimensional organic molecular crystal film grown on the liquid surface. When the two are in full contact, the second solid substrate is slowly lifted away from the liquid surface, and the second two-dimensional organic molecular crystal film 32 adheres to the UV anti-viscosity film and is rinsed and dried.

[0091] For example Figure 3In the third row, the entire second solid-phase substrate is flipped over and suspended on an adjustable cantilever on the 2D material transfer platform. The upper and lower crystals are aligned under an optical microscope. Specifically, "alignment" means that, in vertical projection, at least 20% of the second 2D organic molecular crystal film intersects with the first 2D organic molecular crystal film, at least 20% of the second 2D organic molecular crystal film intersects with the capture layer, and at least 30% of the first 2D organic molecular crystal film is uncovered. After alignment, the cantilever is lowered to ensure full contact between the UV anti-viscosity film (alignment is observed using a microscope; the lowering process can be observed directly from the side and combined with microscopic observation; the UV anti-viscosity film is easier to discern than the second 2D organic molecular crystal film) and the first solid-phase substrate, which is covered with the first 2D organic molecular crystal film (similarly, the first solid-phase substrate is easier to discern than the first 2D organic molecular crystal film and the capture layer). Subsequently, the UV anti-viscosity film is irradiated with appropriate UV light to make the UV anti-viscosity film lose its viscosity. After slowly lifting the second solid phase substrate, the second two-dimensional organic molecular crystal film and the glass carrier (second solid phase substrate) can be peeled off, and finally the heterojunction preparation with the upper and lower crystals aligned can be achieved.

[0092] This makes it easy to ensure full contact between the second 2D organic molecular crystal film and the capture layer, as well as between the second 2D organic molecular crystal film and the first 2D organic molecular crystal film, while also ensuring that the exposed portion of the first 2D organic molecular crystal film is of a size and shape suitable for electrode placement. This ensures that the desired device structure can be assembled while also ensuring atomically flat interfaces between the layers.

[0093] Specifically, the UV anti-viscosity film is selected from one of Lion 6360-15, Lion 6360-20, Lion 6360-25, and Lion 6360-95; in the step of irradiating the UV anti-viscosity film with ultraviolet light to make it lose its viscosity, the light wavelength is 365nm, the light intensity is 1mW / cm 2 ~50 mW / cm 2 The irradiation time is 10s~30s. Most preferably, the UV anti-viscosity film is Lion 6360-15; in the step of irradiating the UV anti-viscosity film with ultraviolet light to make it lose its viscosity, the light intensity is 10 mW / cm 2 , the irradiation time is 30s. It should be noted that the connection method between the UV anti-viscosity film and the second solid phase substrate does not rely on the viscosity of the UV anti-viscosity film itself, but uses another connection method. For example, the edges and corners of the UV anti-viscosity film are fixed to the transparent glass plate with tape, or another adhesive is used to stick the UV anti-viscosity film to the second solid phase substrate in advance. In this way, after UV irradiation and when the second solid phase substrate is lifted, the UV anti-viscosity film will not fall on the first solid phase substrate.

[0094] Due to the high randomness of contact and lifting, it is more difficult when the active layer is composed of three layers. Similarly, the third two-dimensional organic molecular crystal film can also use UV anti-viscosity film and two-dimensional material transfer platform to achieve the transfer and heterogeneous stacking of two-dimensional organic molecular crystals.

[0095] That is, a third solid phase substrate having a UV anti-viscosity film on one side is brought into contact with the third liquid phase substrate so that the third two-dimensional organic molecular crystal film adheres to the UV anti-viscosity film, and the third solid phase substrate is lifted and dried;

[0096] The first solid substrate and the third solid substrate are contacted so that the second two-dimensional organic molecular crystal film and the third two-dimensional organic molecular crystal film face each other, so that the third two-dimensional organic molecular crystal film partially overlaps the second two-dimensional organic molecular crystal film and the remaining portion overlaps the first two-dimensional organic molecular crystal film, and the first two-dimensional organic molecular crystal film still has an exposed portion, and the third two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film form another type II band heterojunction;

[0097] The UV anti-sticking film is irradiated with ultraviolet light to make it lose its stickiness, and the third solid phase substrate is peeled off.

[0098] When aligning the third two-dimensional organic molecular crystal film, for example, at least 15% of the area of the third two-dimensional organic molecular crystal film may intersect with the second two-dimensional organic molecular crystal film, and at least 10% of the area of the first two-dimensional organic molecular crystal film may be uncovered.

[0099] Implementation Cases

[0100] First, a 3 mg / mL PMMA (polymethyl methacrylate) chlorobenzene solution was prepared and evenly coated on the SiO2 / Si substrate using spin coating. The solution was then annealed at 120°C for 10 minutes to form a PMMA capture layer approximately 10 nm thick. This capture layer effectively regulates the charge capture and release dynamics, playing an important role in simulating synaptic plasticity.

[0101] Next, a 0.8 mg / mL solution of DTT-8 in chlorobenzene and a 0.1 mg / mL solution of TFT-CN in chlorobenzene were prepared. These solutions were then dropwise applied to a glycerol substrate. After the chlorobenzene solvent completely evaporated, approximately 14 nm thick DTT-8 and 10 nm thick TFT-CN two-dimensional organic molecular crystal films were formed on the glycerol substrate, respectively. The use of a glycerol substrate effectively suppressed the coffee ring effect, ensuring uniformity and high film quality.

[0102] Subsequently, the DTT-8 2D organic molecular crystal film prepared on the glycerol substrate was transferred to a SiO2 / Si substrate covered with a PMMA capture layer using a contact lift operation. Next, the TFT-CN 2D organic molecular crystal film was transferred onto the DTT-8 film using a UV-sensitive adhesive film, successfully constructing a type II bandgap heterojunction structure.

[0103] At this time, observe under an optical microscope. Figure 5 ( Figure 5 The "substrate" in the figure refers to the first solid phase substrate on which the PMMA capture layer is formed. As shown in FIG, the surface of the film is smooth, the edges are clearly discernible, and the morphology is regular and uniform, indicating that the assembly quality of the two-dimensional organic molecular crystal heterojunction is high.

[0104] Using an optical microscope and a probe mechanical transfer technique, Au electrodes were deposited on the surface of the DTT-8 film and Ag electrodes on the surface of the TFT-CN film, ultimately constructing a complete synaptic device. From top to bottom, the device consists of an Ag / Au electrode, a DTT-8 / TFT-CN two-dimensional organic molecular crystal heterojunction, a PMMA capture layer, and a SiO2 / Si substrate.

[0105] Reference Figure 4 The HOMO curve represents the top of the valence band; the LUMO curve represents the bottom of the conduction band; the circled e represents electrons, and the arrow above indicates that near the contact interface of the two materials, electrons move from the LUMO of DTT-8 to the LUMO of TFT-CN; the circled h represents holes, and the arrow below indicates that near the contact interface of the two materials, holes move from the HOMO of TFT-CN to the HOMO of DTT-8. The type II band arrangement of the heterojunction composed of DTT-8 and TFT-CN demonstrates its efficient carrier separation mechanism.

[0106] The polarization sensitivity of the device was tested and the results were as follows: Figure 6 As shown, under 365 nm polarized light illumination (polarization angles of 0° and 90°), the fabricated synaptic device exhibited significant polarization-sensitive synaptic behavior. The dichroic ratio (δ) of its postsynaptic current reached a high of 10.0, far exceeding the theoretical δ value (3.41) for pure DTT-8 two-dimensional organic molecular crystals. This result demonstrates that by synergizing heterojunction band engineering with the anisotropy of organic single crystal materials, combined with the capture mechanism of minority carriers in the trapping layer, the sensitivity limitations of traditional polarization-sensitive synaptic devices have been successfully overcome, providing a high-performance hardware foundation for intelligent polarization sensing and light-controlled neural computing.

[0107] This application lies at the intersection of optoelectronic materials and neuromorphic computing. Through ingenious heterojunction design, the efficient polarization detection advantage of the "intrinsic linear dichroism" of two-dimensional organic molecular crystals is combined with the efficient driving characteristics of the heterojunction's built-in electric field, achieving synergistic optimization of material performance. This design not only effectively overcomes the limitations of the material's intrinsic anisotropy, but also enables the device to achieve breakthrough progress in high polarization sensitivity and superior photoelectric response characteristics. It is suitable for bionic visual perception, polarization imaging, and light-controlled neuromorphic systems, providing strong technical support for the development of future intelligent perception technologies and promoting the leapfrog development of polarization visual imaging technology.

[0108] Throughout this specification, references to terms such as "one embodiment," "certain embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" indicate that a specific feature, structure, material, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative uses 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 any one or more embodiments or examples.

[0109] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for preparing an organic synaptic device with high polarization sensitivity, characterized in that: The following steps are involved: preparing a capture layer on a first solid substrate; preparing a first two-dimensional organic molecular crystal film with a smaller area than the capture layer on a first liquid phase substrate, and preparing a second two-dimensional organic molecular crystal film with a smaller area than the capture layer on a second liquid phase substrate; transferring the first two-dimensional organic molecular crystal film onto the capture layer; Transferring the second two-dimensional organic molecular crystal film onto the capture layer so that the first two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film intersect in shape and form a type II energy band heterojunction; preparing electrodes on the surfaces of the first two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film, respectively, to obtain the organic synapse device with high polarization sensitivity; Before the step of preparing electrodes on the surfaces of the first two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film, the method further includes the following steps: forming a third two-dimensional organic molecular crystal film having an area smaller than that of the first two-dimensional organic molecular crystal film on a third liquid substrate; transferring the third two-dimensional organic molecular crystal film to the first solid substrate so that a portion of the third two-dimensional organic molecular crystal film overlaps the second two-dimensional organic molecular crystal film and a remaining portion overlaps the first two-dimensional organic molecular crystal film, so that the third two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film form another type II band heterojunction; The electrodes include a second electrode in contact with the second two-dimensional organic molecular crystal film, and a first electrode in contact with both the first two-dimensional organic molecular crystal film and the third two-dimensional organic molecular crystal film.

2. The method for preparing an organic synaptic device with high polarization sensitivity according to claim 1, wherein: The step of transferring the second two-dimensional organic molecular crystal film onto the capture layer so that the first two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film intersect in shape and form a type II energy band heterojunction comprises: contacting the second liquid substrate with a second solid substrate having a UV anti-viscosity film on one side so that the second two-dimensional organic molecular crystal film adheres to the UV anti-viscosity film, and lifting and drying the second solid substrate; The first solid substrate is brought into contact with the second solid substrate so that the first two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film face each other, so that the first two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film intersect and form a type II energy band heterojunction; The UV anti-viscosity film is irradiated with ultraviolet light to make it lose its viscosity, and the second solid phase substrate is peeled off.

3. The method for preparing an organic synaptic device with high polarization sensitivity according to claim 2, wherein: The step of placing the first two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film face to face and contacting the first solid substrate with the second solid substrate so that the first two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film intersect in shape and form a type II energy band heterojunction comprises: placing the first solid substrate on a platform with the first two-dimensional organic molecular crystal film facing upward; Fixing the transparent second solid substrate in suspension on a cantilever with the second two-dimensional organic molecular crystal film facing downward; Adjusting the cantilever so that the vertical projection of the second two-dimensional organic molecular crystal film is within the range of the capture layer, and the vertical projection of the second two-dimensional organic molecular crystal film intersects with the shape of the first two-dimensional organic molecular crystal film; The cantilever is lowered until the first two-dimensional organic molecular crystal film contacts the second two-dimensional organic molecular crystal film.

4. The method for preparing an organic synaptic device with high polarization sensitivity according to claim 2, wherein: The UV anti-viscosity film is selected from one of Lion 6360-15, Lion 6360-20, Lion 6360-25 and Lion 6360-95; In the step of irradiating the UV anti-viscosity film with ultraviolet light to make it lose its viscosity, the wavelength of the light is 365nm and the intensity of the light is 1mW / cm 2 ~50 mW / cm 2 , the irradiation time is 10s~30s.

5. The method for preparing an organic synaptic device with high polarization sensitivity according to claim 4, wherein: The UV anti-viscosity film is Lion 6360-15; In the step of irradiating the UV anti-viscosity film with ultraviolet light to make it lose its viscosity, the light intensity is 10 mW / cm 2 , the irradiation time is 30s.

6. An organic synaptic device with high polarization sensitivity, characterized in that An organic synapse device with high polarization sensitivity is made by the preparation method of any one of claims 1 to 5, and includes, from bottom to top, a first solid substrate, a capture layer and an active layer, the active layer including a first two-dimensional organic molecular crystal film and a second two-dimensional organic molecular crystal film both in contact with the capture layer, the second two-dimensional organic molecular crystal film is partially stacked on the first two-dimensional organic molecular crystal film to form a type II band heterojunction, a first electrode is provided on the surface of the first two-dimensional organic molecular crystal film, and a second electrode is provided on the second two-dimensional organic molecular crystal film; the active layer also includes a third two-dimensional organic molecular crystal film, the third two-dimensional organic molecular crystal film is partially stacked on the second two-dimensional organic molecular crystal film, and the remaining part is stacked on the first two-dimensional organic molecular crystal film, the third two-dimensional organic molecular crystal film and the second two-dimensional organic molecular crystal film form another type II band heterojunction; the first electrode is in contact with both the first two-dimensional organic molecular crystal film and the third two-dimensional organic molecular crystal film.

7. The organic synaptic device with high polarization sensitivity according to claim 6, characterized in that The linear polarization dichroic ratio is ≥10.

8. The organic synaptic device with high polarization sensitivity according to claim 6, characterized in that The thickness of the first two-dimensional organic molecular crystal film is 1nm~100nm, the thickness of the second two-dimensional organic molecular crystal film is 1nm~100nm, the thickness of the capture layer is 5nm~15nm, the thickness of the first electrode is 10nm~100nm, and the thickness of the second electrode is 10nm~100nm.

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