Multiband photoresponse neuronal synapse device and array based on two-dimensional and organic heterostructure, and application of multiband photoresponse neuronal synapse device

Abstract

The invention provides a multiband photoresponse nerve synapse device based on a two-dimensional and organic heterostructure, an array and application, and belongs to the technical field of organic electric solid-state devices. The device provided by the invention adopts a three-end bottom gate top contact structure and comprises a gate substrate, an insulating layer, a channel layer and a source / drain electrode, and the channel layer forms an II-type heterojunction by a two-dimensional semiconductor material with a narrow-band gap characteristic and an organic semiconductor material. The heterostructure realizes ultraviolet to far infrared (365nm-10 [mu] m) multiband photoelectric response, and shows synaptic plasticity under light pulse modulation, including short-term enhancement, long-term enhancement and learning-forgetting-re-learning characteristics. Large-area array preparation of the device can be realized through methods such as chemical vapor deposition, solution spin coating, jet printing or layer-by-layer self-assembly. The technology not only can be used for brain-like learning and memory simulation, but also can be applied to the fields of sensing and memory integrated intelligent systems, optical neural networks, artificial vision, multi-mode intelligent sensing and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic electric solid-state devices, relates to brain-like neural electronics and novel optoelectronic information devices, and relates to a preparation method of the devices and application of the devices in optoelectronic synapse networks, in particular to a multi-band light response neural synapse device, array and application based on a two-dimensional and organic heterostructure, which can be widely applied to frontiers such as artificial intelligence hardware, flexible electronics, intelligent vision and optical neural networks. BACKGROUND

[0002] With the rapid development of artificial intelligence, the Internet of Things and intelligent sensing systems, the traditional electronic information system with a "sensing-storage-computing" separated architecture as the core has been difficult to meet the intelligent processing needs of high efficiency and low power consumption. In recent years, brain-like neural morphological devices have become an important research direction of the new generation of intelligent computing because they can realize the fusion of learning, memory and perception at the hardware level. Among many neural morphological devices, optical neural synapse devices are considered as the key basis of optical artificial neural networks and sensing-storage integrated systems because they can directly use light signals as synaptic stimuli to realize the integration of "perception-memory". However, the existing optical synapse devices still have the following technical bottlenecks:

[0003] 1. Limited spectral response range: The current mainstream optical synapse devices are mostly based on single-band or narrow-spectrum response materials such as oxide semiconductors, organic polymers or single two-dimensional materials, which are difficult to simultaneously realize multi-modal responses in the ultraviolet, visible and infrared bands. The paper "Liu S, Zhang L, Ma B, et al. High-Performance Ultraviolet to Near-Infrared Antiambipolar Photodetectors Based on 1D CdSe Nanorods" (Advanced Functional Materials, 2018, 28(16): 1706818) reports a single-band photodetector based on one-dimensional CdSe nanorods, which can only respond to ultraviolet light. x Se 1-x / 2DTe Heterojunction[J]. ACS Applied Materials & Interfaces, 2024, 16(36): 47808-47819.》, Tao J-J, Jiang J, Zhao S-N, et al. Fabrication of 1DTe / 2DReS2 Mixed-Dimensional van der Waals p-n Heterojunction for High-Performance Phototransistor[J]. ACS Nano, 2021, 15(2): 3241-3250.》, Zhao D, Chen Y, Jiang W, et al. Gate-Tunable Photodiodes Based on Mixed-Dimensional Te / MoTe2 Van der Waals Heterojunctions[J]. Advanced Electronic Materials, 2021, 7(5): 2001066.》, Peng H, Li H, Guo E, et al. High-Performance Te Nanowires / MoS2 / Polyimine Nanocomposite-Based Self-Healable, Recyclable and Screen-Printable Flexible Photodetector for Image Sensing[J]. Advanced Functional Materials, 2024, 34(24): 2314743.》. Although Te nanowires or Te two-dimensional devices have good detection ability in the near-infrared region, their spectral response range is limited and lacks biomimetic synaptic characteristics.At the same time, the paper "Shen T, Li W, Zhao Y, et al. A Hybrid Acceptor-Modulation Strategy: Fluorinated Triple-AcceptorArchitecture for Significant Enhancement of Electron Transport in High-Performance Unipolar n-Type Organic Transistors[J]. Advanced Materials, 2023,35(8): 2210093." Inkjet-Printed, Coplanar Electrolyte-Gated Organic Field-Effect Transistors onFlexible Substrates: Fabrication, Modeling, and Applications in Biodetection[J]. Advanced Materials Technologies, 2023, 8(2): 2200300.", paper "Chen Z, LiR, Jia Q, et al. Dual-Engineered DPP Polymers: Synergistic Hydrogen Bondingand Ring-Fusion for High-Mobility Organic Field-Effect Transistors[J].Angewandte Chemie International Edition, 2025, n / a(n / a): e202514768. 》 and the paper "Cui T, Luo N, Zhang Z, et al. A Fused Diketopyrrolopyrrole Derivative for Single-Crystal Visible-NIR Organic Phototransistor[J]. Small Methods, 2025, 9(8): 2402250." synaptic devices using DPP polymers (similar to organic semiconductors such as PDPP4T, PDPP2T, DPP-TDTT, and DPP-PPV) achieve non-volatile weighting in the ultraviolet to visible light band by modulating the trapped states.For example, the paper "Tang D, DuZ, Xie Y, et al. UV to NIR Broadband Flexible Photodetector Based on Solution-Processed MoS2 / PDPP3T Inorganic–Organic Hybrid Heterostructures[J]. Advanced Materials Interfaces, 2024, 11(17): 2301065." mentions that the MoS2 / PDPP3T inorganic-organic hybrid heterostructure was used to construct a broadband flexible photodetector from ultraviolet to near-infrared. As mentioned above, neither single materials nor inorganic / organic heterostructures have yet covered the ultraviolet and far-infrared bands.

[0004] 2. Poor Material System Compatibility: Purely inorganic or purely organic systems suffer from deficiencies in band structure matching, interface stability, and processing compatibility, limiting the precise control of synaptic responses. On the one hand, mainstream high-performance far-infrared materials (such as HgCdTe) contain the highly toxic element mercury, and their preparation processes are complex, have poor uniformity, low yield, and high cost, thus limiting large-scale applications. On the other hand, while novel low-dimensional materials (such as quantum dots) have shown potential in room-temperature detection, they still face significant challenges in large-area preparation, stability, dark current control, and response speed.

[0005] 3. Limited functionality and lack of dynamic adaptability: See the papers "Cao X, Lei Z, Huang B, et al. Non-Layered Te / In(2) S(3) Tunneling Heterojunctions with Ultrahigh Photoresponsivity and Fast Photoresponse[J]. Small, 2022, 18(18): e2200445.", "He X, Zhang L, Hong W, et al. Self-Powered Te / Wse2 Van Der WaalsHeterojunction Photodetectors With High Light On / Off Ratio And Fast Response[J]. Advanced Optical Materials, 2023, 11(17): 2300319.", and "Zhang Y, Zhang F, Wu L, et al. Van der Waals Integration of Bismuth Quantum Dots–Decorated Tellurium Nanotubes (Te@Bi) Heterojunctions and Plasma-Enhanced Optoelectronic Applications[J]. Traditional optical detection or storage devices, as described in Small, 2019, 15(47): 1903233, primarily achieve "photo-to-electric conversion" and have not yet effectively simulated the dynamic behavior of biological synapses (such as short-term enhancement, long-term enhancement, and relearning characteristics). The "sensor-processor separation" architecture, which can only achieve "photo-to-electric conversion," will cause huge data migration delays and power consumption when processing massive amounts of redundant optical information. Common heterogeneous structure designs often focus on improving charge separation efficiency or mechanical stability, without fully exploring the fusion of multi-band collaborative detection and synaptic behavior. Furthermore, they cannot directly correlate multiple temporal information sets, resulting in deficiencies in preprocessing functions such as weighting, filtering, and feature extraction.

[0006] 4. Difficulty in fabrication and array integration: Most high-performance photosynapses are still at the experimental single-device stage, lacking the process for large-area array fabrication.

[0007] With the continuous exploration of emerging materials, two-dimensional materials (such as graphene, black phosphorus, transition metal chalcogenides, etc.) have shown great potential in the field of far-infrared detection. With their unique physical properties, these materials can provide higher carrier mobility, stronger light-matter interaction and a wider spectral response range.

[0008] Against this backdrop, the synaptic synergistic response of far-infrared and ultraviolet multi-band structures can mimic and surpass the multimodal sensing fusion capabilities of biological systems, thereby driving infrared detection technology towards "sensing-memory-computing integration" and "brain-like intelligence." To address the aforementioned issues, the inventors began exploring heterojunction structures of two-dimensional materials and organic semiconductors, leveraging the former's superior carrier mobility and broad-spectrum absorption characteristics, and the latter's rich molecular design space and flexible fabrication advantages. These heterostructures not only achieve tunable type II alignment, improving photogenerated carrier separation efficiency, but also exhibit tunable synaptic plasticity across different light bands. However, existing research is largely limited to the near-infrared or visible light regions, and synaptic photoresponse behavior has not yet been achieved across the entire ultraviolet to far-infrared spectrum; simultaneously, the array-based construction and multi-band synergistic learning mechanisms of two-dimensional / organic heterostructures still lack systematic research. Therefore, a novel opto-neural synaptic device that combines multi-band photoresponse, brain-like synaptic plasticity, and array-based fabrication capabilities is urgently needed to provide crucial support for realizing integrated sensing and intelligent perception systems. Summary of the Invention

[0009] This invention is made to solve the above-mentioned problems, and aims to provide a multi-band optically responsive neural synapse device, array and application based on two-dimensional and organic heterostructure.

[0010] This invention provides an application of a multi-band photoresponsive neural synapse device based on a two-dimensional and organic heterostructure in memory and brain-like learning. The device features a three-terminal bottom-gate top contact structure, using a type II heterostructure formed by a band-matched two-dimensional material layer and an organic semiconductor layer as the channel layer. The two-dimensional material layer is a narrow bandgap two-dimensional material with a bandgap of less than 0.3 eV, and the organic semiconductor layer is made of DPP polymer. In application, multi-band light pulses are used to simulate information input during the human brain's learning process, and the output current of the device simulates memory intensity. Brain-like learning is achieved by applying / removing multi-band light pulses to the device and using the multi-band light pulses and output current to simulate the cognitive process of learning-forgetting-relearning in human memory. The multi-band light pulses are far-infrared light of 8 μm to 14 μm and / or 315 nm to 400 nm. nm ultraviolet light.

[0011] In the application of the multi-band optical response neural synapse device based on two-dimensional and organic heterostructure provided by the present invention in memory and brain-like learning, it may also have the following characteristics: wherein the multi-band optical pulses include optical pulses of different intensities, frequencies, frequencies, and durations.

[0012] In the application of the multi-band light-responsive neural synapse device based on a two-dimensional and organic heterostructure provided by this invention in memory and brain-like learning, it may also have the following features, including the following steps: A10, learning stage: applying multi-band light pulses to the multi-band light-responsive neural synapse device based on a two-dimensional and organic heterostructure to enhance its output current to a preset level, wherein the output current is used to simulate the memory intensity of the learning stage in cognitive behavior; A20, forgetting stage: stopping the application of multi-band light pulses to cause the output current to decay, thereby using the output current to simulate the memory intensity of the forgetting stage in cognitive behavior; A30, relearning stage: applying multi-band light pulses again to the multi-band light-responsive neural synapse device based on a two-dimensional and organic heterostructure, wherein in the relearning stage, the number of multi-band light pulses required to restore the output current to the preset level is less than the number of multi-band light pulses required in the learning stage, thereby using the output current to simulate the memory intensity of the relearning stage in cognitive behavior.

[0013] In the application of the multi-band photoresponsive neural synapse device based on two-dimensional and organic heterostructure provided by the present invention in memory and brain-like learning, it may also have the following features: wherein the multi-band photoresponsive neural synapse device based on two-dimensional and organic heterostructure includes: a gate substrate; an insulating layer disposed on the gate substrate; a channel layer including a two-dimensional material layer and an organic semiconductor layer, wherein the two-dimensional material layer is disposed on the insulating layer and the organic semiconductor layer is disposed on the two-dimensional material layer; and a source / drain electrode disposed on the organic semiconductor layer.

[0014] In the application of the multi-band optically responsive neural synapse device based on two-dimensional and organic heterostructure provided by the present invention in memory and brain-like learning, it may also have the following features: wherein the gate substrate includes a lightly, moderately, heavily or extremely heavily p-type doped silicon wafer, the insulating layer is made of SiO2, HfO2, ZrO2 or Al2O3, and the source / drain electrode is made of Au, Cr / Au or Pt / Au.

[0015] Preferably, the gate substrate is a heavily p-type doped silicon wafer.

[0016] Preferably, the insulating layer is made of SiO2.

[0017] Preferably, the source / drain electrode material is Au.

[0018] In the application of the multi-band optically responsive neural synapse device based on two-dimensional and organic heterostructure provided by the present invention in memory and brain-like learning, it may also have the following characteristics: wherein the material of the two-dimensional material layer includes tellurium, black phosphorus, bismuth telluride, molybdenum telluride, palladium diselenide or platinum diselenide, the thickness of the two-dimensional material layer is 10 nm to 50 nm, the DPP polymer includes PDPP4T, PDPP2T, DPP-TDTT or DPP-PPV, and the thickness of the organic semiconductor layer is 20 nm to 80 nm.

[0019] Preferably, the material of the two-dimensional material layer is tellurium.

[0020] Preferably, the DPP polymer is PDPP4T.

[0021] In the application of the multi-band photoresponsive neural synapse device based on two-dimensional and organic heterostructure provided by this invention in memory and brain-like learning, it can also have the following features: the preparation method of the multi-band photoresponsive neural synapse device based on two-dimensional and organic heterostructure includes the following steps: B10, preparing a uniform and continuous thin film of two-dimensional material with a band gap of less than 0.3 eV on a gate substrate with an insulating layer by chemical vapor deposition, as a two-dimensional material layer; B20, spin-coating or vapor-depositing DPP polymer on the two-dimensional material layer and annealing to form a uniform type II heterostructure of two-dimensional material and organic semiconductor, as a channel layer; B30, vapor-depositing source / drain electrodes on the channel layer, finally obtaining the multi-band photoresponsive neural synapse device based on two-dimensional and organic heterostructure.

[0022] In the application of the multi-band optically responsive neural synapse device based on two-dimensional and organic heterostructure provided by the present invention in memory and brain-like learning, it may also have the following characteristics: in step B10, the deposition temperature is 5℃~15℃ and the deposition rate is 0.5 nm / min~5 nm / min; in step B20, the annealing temperature is 80℃~160℃ and the annealing time is 30min~90min.

[0023] This invention also provides an application of a multi-band optically responsive neural synaptic device array based on a two-dimensional and organic heterostructure, characterized in that the multi-band optically responsive neural synaptic device array based on a two-dimensional and organic heterostructure includes any of the aforementioned multi-band optically responsive neural synaptic devices based on a two-dimensional and organic heterostructure, wherein the multi-band optically responsive neural synaptic device array based on a two-dimensional and organic heterostructure is used to perform parallel weight updates and / or signal processing on multiple multi-band optical pulses, thereby simulating the preprocessing function of the retina, and the multi-band optically responsive neural synaptic device array based on a two-dimensional and organic heterostructure is used to perform synchronous or asynchronous responses to multi-band optical pulses.

[0024] In the application of the multi-band photoresponsive neural synaptic device array based on two-dimensional and organic heterostructure provided by the present invention, it can also have the following features: the fabrication method of the multi-band photoresponsive neural synaptic device array based on two-dimensional and organic heterostructure includes the following steps: B10, a uniform and continuous thin film of two-dimensional material with a band gap of less than 0.3 eV is prepared on a gate substrate with an insulating layer by chemical vapor deposition as a two-dimensional material layer; B20, DPP polymer is spin-coated or vapor-deposited on the two-dimensional material layer and annealed to form a uniform type II heterostructure of two-dimensional material and organic semiconductor as a channel layer; C30, photoresist is spin-coated on the channel layer, pre-baked and then photolithography and development of the preset array arrangement are performed under ultraviolet light, and finally the preset array of channel layers is obtained by RIE treatment and resist removal; C40, source / drain electrodes are vapor-deposited on the array of channel layers using a mask to obtain the multi-band photoresponsive neural synaptic device array based on two-dimensional and organic heterostructure.

[0025] In the application of the multi-band photoresponsive neural synaptic device array based on two-dimensional and organic heterostructure provided by the present invention, it may also have the following features: in step C30, the spin coating speed of the photoresist is 2000 rpm to 3000 rpm, the spin coating time is 40 s to 60 s, the pre-baking temperature is 90℃ to 100℃, the baking time is 10 s to 60 s, the exposure time during photolithography is 10 s to 60 s, the RIE treatment uses carbon tetrafluoride gas for 10 s to 60 s, and the photoresist is removed using acetone and isopropanol for cleaning.

[0026] The beneficial effects of this invention are:

[0027] (1) The core innovation of this invention lies in the first-time combination of narrow-bandgap two-dimensional materials with organic semiconductors. Through bandgap engineering design, a heterojunction is constructed and type II band alignment is achieved, thereby enabling simultaneous response in multiple bands, including far-infrared (8μm~14μm) and ultraviolet (315nm~400nm). In addition, this invention provides a light pulse-dependent synaptic plasticity modulation mechanism for multi-band photoresponsive neural synaptic devices based on two-dimensional and organic heterostructures: process modulation from short-term enhancement (STP) to long-term enhancement (LTP) (mainly studying the specific synaptic plasticity in the far-infrared and ultraviolet bands). This material and dual-band synaptic logic have not been reported in the prior art and are expected to promote the development of synaptic devices with synergistic responses in both far-infrared and ultraviolet bands.

[0028] (2) This invention achieves simulation of photoresponse and synaptic plasticity in both far-infrared and ultraviolet bands, breaking through the limitations of traditional photodetectors (square wave) in terms of response band and memory function. It provides a new path for multi-band fusion sensing and dynamic neural network computation, filling the gap in existing photosynaptic devices in the far-infrared band. This differs from previously reported devices such as Te / MoSe2, Bi2Se3 / Te@Se, Te / WS2, and Te / CdS. x Se 1-x / 2 Unlike other photodetectors such as Te@Bi, whose response range is limited to the ultraviolet-near-infrared band (detecting only up to 808 nm), this invention uses band engineering to match the bands of narrow-bandgap two-dimensional materials with those of organic semiconductors (wide-bandgap materials), and controls the thickness of different photosensitive layers to construct a heterostructure with type II band alignment, giving it the advantages of both broad-spectrum absorption and high carrier separation efficiency.

[0029] (3) In terms of material design, the multi-band optical response neural synapse device based on two-dimensional and organic heterostructure of the present invention has the advantages of low cost and solution-processable characteristics through narrow bandgap two-dimensional material / organic semiconductor composite structure, which overcomes the bottleneck of controllability and large-scale preparation of traditional inorganic / inorganic heterojunctions, and provides new possibilities for the practical application of optical neuromorphic devices.

[0030] (4) The multi-band photoresponsive neural synapse device based on two-dimensional and organic heterostructure of the present invention exhibits synaptic plasticity and photo-enhanced memory effect. The device shows significant current gain characteristics under different light intensities, frequencies and durations. Under 5 s of continuous 10 μm and 365 nm light pulse stimulation, memory retention times of up to 35 s and 107 s can be achieved, respectively; and it also shows excellent dynamic regulation ability of learning-forgetting in the simulation of the learning-forgetting-relearning process of the human brain, which is better than most reported Te-based pure photodetectors (without memory function), which makes it have the characteristics of spatiotemporal dynamic information processing.

[0031] (5) The multi-band photoresponsive neural synapse device based on two-dimensional and organic heterostructure of the present invention not only realizes tunable synaptic-like response and memory effect, which is highly consistent with the human "learning-forgetting-relearning" behavior, but also successfully constructs a synaptic functional model that can simulate the entire process of human learning, forgetting and relearning, providing important device support and theoretical foundation for the design and implementation of efficient artificial neural network systems. Therefore, based on the memory retention and decay characteristics of the device, its postsynaptic current (EPSC) enables the system to produce a highly discriminative state-dependent response to light pulse sequences. This mechanism is highly isomorphic to the plasticity of biological synapses, and realizes spatiotemporal information encoding through the temporal decay of signal intensity. It is expected to complete the spatiotemporal feature extraction of dynamic light signals at the sensing end, replacing complex matrix operations.

[0032] (6) The multi-band photoresponsive neural synapse device array based on two-dimensional and organic heterostructure of the present invention has been successfully fabricated, which can simultaneously realize parallel weight update or signal processing of multiple multi-band light pulses. This advantage, which is consistent with the parallel processing mode of the brain, can simulate the preprocessing function of the retina. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of a multi-band optically responsive neural synapse device based on a two-dimensional and organic heterostructure, according to an embodiment of the present invention.

[0034] Figure 2 This is a flowchart illustrating the fabrication method of a multi-band optically responsive neural synaptic device based on a two-dimensional and organic heterostructure, according to an embodiment of the present invention.

[0035] Figure 3 This is a SEM image of a multi-band optically responsive neural synapse device based on a two-dimensional and organic heterostructure prepared according to an embodiment of the present invention.

[0036] Figure 4 This is a Raman spectral characterization of the channel layer of a multi-band optically responsive neural synapse device based on a two-dimensional and organic heterostructure prepared according to an embodiment of the present invention.

[0037] Figure 5 This is a graph showing the photosynaptic response performance of a multi-band photoresponsive neural synaptic device based on a two-dimensional and organic heterostructure, prepared according to an embodiment of the present invention, to multi-band light pulses.

[0038] Figure 6 This is a flowchart illustrating the application of a multi-band optically responsive neural synaptic device based on a two-dimensional and organic heterostructure in memory and brain-like learning, according to an embodiment of the present invention.

[0039] Figure 7 This is a schematic diagram illustrating the dynamic memory behavior of photosynapses under 10 μm pulses in the application of a multi-band optically responsive neural synapse device based on a two-dimensional and organic heterostructure in memory and brain-like learning, according to an embodiment of the present invention.

[0040] Figure 8 This is a schematic diagram illustrating the dynamic memory behavior of photosynapses under 365 nm pulses in the application of a multi-band optically responsive neural synapse device based on a two-dimensional and organic heterostructure in memory and brain-like learning, according to an embodiment of the present invention.

[0041] Figure 9 This is a flowchart illustrating the fabrication method of a multi-band optically responsive neural synaptic device array based on a two-dimensional and organic heterostructure, according to an embodiment of the present invention. Detailed Implementation

[0042] To make the technical means, creative features, objectives and effects of the present invention easy to understand, the following embodiments, in conjunction with the accompanying drawings, specifically illustrate a multi-band optically responsive neural synapse device, array and application based on a two-dimensional and organic heterostructure.

[0043] Example

[0044] Figure 1 This is a schematic diagram of the structure of a multi-band optically responsive neural synapse device based on a two-dimensional and organic heterostructure, according to an embodiment of the present invention.

[0045] like Figure 1 As shown, this embodiment provides a multi-band optically responsive neural synapse device 100 based on a two-dimensional and organic heterostructure, including a gate substrate G, an insulating layer 10, a channel layer 20, and source / drain electrodes 30.

[0046] The gate substrate G serves as the substrate for the multi-band optically responsive neural synapse device 100 based on a two-dimensional and organic heterostructure, and it is a heavily p-type doped silicon wafer.

[0047] An insulating layer 10 is disposed on the gate substrate G, and its material is SiO2 with a thickness of 300 nm.

[0048] The channel layer 20 includes a two-dimensional material layer 21 and an organic semiconductor layer 22.

[0049] A two-dimensional material layer 21 is disposed on the insulating layer 10. The material is Te and the thickness is 50 nm.

[0050] An organic semiconductor layer 22 is disposed on a two-dimensional material layer 21. The material is PDPP4T and the thickness is 20 nm. The energy bands of the two-dimensional material layer 21 and the organic semiconductor layer 22 are matched.

[0051] The source / drain 30 includes a source S and a drain D, both of which are disposed on the organic semiconductor layer 22 and are made of Au.

[0052] Figure 2 This is a flowchart illustrating the fabrication method of a multi-band optically responsive neural synaptic device based on a two-dimensional and organic heterostructure, according to an embodiment of the present invention.

[0053] like Figure 2 As shown, this embodiment also provides a method for fabricating the aforementioned multi-band optically responsive neural synapse device 100 based on a two-dimensional and organic heterostructure, including the following steps:

[0054] B10, a uniform and continuous 50 nm thick tellurium thin film was prepared on a gate substrate G (a heavily p-type doped silicon wafer) with an insulating layer 10 (made of SiO2 with a thickness of 300 nm) by chemical vapor deposition (low temperature deposition temperature of 10℃, deposition rate of 1 nm / min), as a two-dimensional material layer 21.

[0055] B20, PDPP4T is spin-coated onto a two-dimensional material layer 21 and annealed at 100°C for 1 hour to form a 20 nm thick organic semiconductor layer 22. The two-dimensional material layer 21 and the organic semiconductor layer 22 form a uniform type II heterostructure, serving as the channel layer 20.

[0056] B30, source / drain electrode 30 (made of Au) is deposited on channel layer 20, and finally a multi-band photoresponsive neural synapse device 100 based on two-dimensional and organic heterostructure is obtained.

[0057] Figure 3 This is a SEM image of a multi-band optically responsive neural synapse device based on a two-dimensional and organic heterostructure prepared according to an embodiment of the present invention.

[0058] like Figure 3 As shown, the gate substrate G and insulating layer 10 of the multi-band photoresponsive neural synapse device 100 based on two-dimensional and organic heterostructure can be observed as distinct Au (source / drain 30), PDPP4T (organic semiconductor layer 22) and Te (two-dimensional material layer 21) layered structure on the SiO2 / Si substrate. Figure 3 The illustration in the figure is an HRTEM image of the two-dimensional material layer 21 of the multi-band optically responsive neural synapse device 100 based on a two-dimensional and organic heterostructure according to an embodiment of the present invention. The lattice spacing of the two-dimensional material layer 21 is 0.33 nm, corresponding to the (100) plane.

[0059] Figure 4 This is a Raman spectral characterization of the channel layer of a multi-band optically responsive neural synapse device based on a two-dimensional and organic heterostructure prepared according to an embodiment of the present invention.

[0060] like Figure 4 As shown, it is located at 93cm. -1 119cm -1 And 141cm -1 The peaks are highly consistent with the E1-TO, A2, and E2 phonon vibration modes in the two-dimensional material layer 21, respectively; located at 1370 cm⁻¹ -1 1428cm -1 And 1514cm -1These vibrations are attributed to the C=C stretching vibrations in the DPP units of the organic semiconductor layer 22, the local C=C stretching vibrations in the thiophene units, and the delocalized C=C / CC stretching / contraction vibrations, respectively. These vibrations demonstrate the successful construction of the transistor (a multi-band optically responsive neural synapse device 100 based on a two-dimensional and organic heterostructure) and its clear and uniform layering.

[0061] Figure 5 This is a graph showing the photosynaptic response performance of a multi-band photoresponsive neural synaptic device based on a two-dimensional and organic heterostructure, prepared according to an embodiment of the present invention, to multi-band light pulses.

[0062] like Figure 5 As shown, the multi-band photoresponsive neural synapse device 100 based on two-dimensional and organic heterostructure in this embodiment can successfully achieve multi-band photosynaptic responses in the ultraviolet-visible-near-infrared-far-infrared ranges, including 365 nm, 532 nm, 980 nm, 1550 nm and 10 μm, all of which exhibit high responsiveness and continuously enhanced excitatory synaptic behavior.

[0063] Figure 6 This is a flowchart illustrating the application of a multi-band optically responsive neural synaptic device based on a two-dimensional and organic heterostructure in memory and brain-like learning, according to an embodiment of the present invention.

[0064] like Figure 6 As shown, this embodiment uses the aforementioned multi-band optically responsive neural synapse device 100 based on a two-dimensional and organic heterostructure to provide applications of the multi-band optically responsive neural synapse device based on a two-dimensional and organic heterostructure in memory and brain-like learning, including the following steps:

[0065] A10, Learning Phase: Apply multi-band light pulses to the multi-band light-responsive neural synapse device 100 based on a two-dimensional and organic heterostructure to enhance its output current to a set level.

[0066] Among them, the output current is used to simulate the memory intensity of the learning stage in cognitive behavior; the multi-band light pulses include light pulses of different intensities, frequencies, frequencies, and durations.

[0067] A20, Forgetting Stage: Stop applying multi-band light pulses to attenuate the output current, thereby using the output current (the amplitude of the residual current after light removal) to simulate the memory intensity in the forgetting stage of cognitive behavior.

[0068] A30, Relearning Phase: Apply multi-band light pulses again to the multi-band light-responsive neural synapse device 100 based on a two-dimensional and organic heterostructure.

[0069] During the relearning phase, the number of multi-band light pulses required to restore the output current to the set level is less than the number of multi-band light pulses required during the learning phase, thereby using the output current to simulate the memory intensity during the relearning phase in cognitive behavior.

[0070] Figure 7 This is a schematic diagram of the dynamic memory behavior of photosynapses under 10 μm pulses in the application of a multi-band optically responsive neural synapse device based on a two-dimensional and organic heterostructure in memory and brain-like learning, according to an embodiment of the present invention. Figure 8 This is a schematic diagram illustrating the dynamic memory behavior of photosynapses under 365 nm pulses in the application of a multi-band optically responsive neural synapse device based on a two-dimensional and organic heterostructure in memory and brain-like learning, according to an embodiment of the present invention.

[0071] like Figure 7 part a in Figure 7 part b in Figure 8 part a in and Figure 8 As shown in part b, the induced EPSC amplitude (residual current amplitude) increases with the increase of the duration and frequency of the 10μm and 365nm light pulses, confirming the photocontrolled synaptic weight enhancement effect and indicating that the learning effect of the learning stage in step A10 is improved. After the light pulses are removed, the EPSC amplitude (residual current amplitude) increases with the increase of the duration and frequency of the light pulses, confirming the memory enhancement in steps A10 to A20 and the dynamic transformation behavior from short-term memory (STM) to long-term memory (LTM).

[0072] like Figure 7 As shown in section c, three sets of light pulse sequences at different stages were designed to simulate the "learning-forgetting-relearning" cognitive behavior in the human brain. Under 10 μm light pulse stimulation, the initial application of 15 light pulses induced a significant increase in EPSC amplitude (residual current amplitude). When the light pulse sequence was removed, the photocurrent decayed to a certain level. After the first forgetting stage, only 3 pulses were needed to reach the same level as the first training stage, which was far fewer than the number of pulses required for the first learning stage. Then, the second forgetting process occurred, decaying to a similar level as before. At this point, only 2 pulses were needed to restore the initial learning level.

[0073] like Figure 8 As shown in section c, the number of pulses for the three learning sessions under 365 nm light stimulation were 15, 7, and 6, respectively, and all achieved the same learning level.

[0074] like Figure 7 and Figure 8As shown, the multi-band optically responsive neural synapse device 100 based on a two-dimensional and organic heterostructure in this embodiment not only achieves tunable synaptic-like responses and memory effects, highly consistent with human "learning-forgetting-relearning" behavior, but also successfully constructs a synaptic functional model that can simulate the entire process of human learning, forgetting, and relearning (memory and brain-like learning), providing important device support and theoretical foundation for the design and implementation of efficient artificial neural network systems. Therefore, based on the device's memory retention and decay characteristics, its postsynaptic EPSC amplitude (excitatory postsynaptic current amplitude) enables the system to produce highly discriminative state-dependent responses to light pulse sequences. This mechanism is highly isomorphic to biological synaptic plasticity, achieving spatiotemporal information encoding through temporal attenuation of signal intensity. It is expected to complete the spatiotemporal feature extraction of dynamic optical signals at the sensing end, replacing complex matrix operations.

[0075] This embodiment also provides a multi-band photoresponsive neural synapse device array based on a two-dimensional and organic heterostructure, which has 6×6 array-distributed multi-band photoresponsive neural synapse devices 100 based on a two-dimensional and organic heterostructure.

[0076] Figure 9 This is a flowchart illustrating the fabrication method of a multi-band optically responsive neural synaptic device array based on a two-dimensional and organic heterostructure, according to an embodiment of the present invention.

[0077] like Figure 9 As shown, the fabrication method of the multi-band optically responsive neural synaptic device array based on two-dimensional and organic heterostructures in this embodiment includes the following steps:

[0078] B10, a uniform and continuous 50 nm thick tellurium thin film was prepared on a gate substrate G (a heavily p-type doped silicon wafer) with an insulating layer 10 (made of SiO2 with a thickness of 300 nm) by chemical vapor deposition (low temperature deposition temperature of 10℃, deposition rate of 1 nm / min), as a two-dimensional material layer 21.

[0079] B20, PDPP4T is spin-coated onto a two-dimensional material layer 21 and annealed at 100°C for 1 hour to form a 20 nm thick organic semiconductor layer 22. The two-dimensional material layer 21 and the organic semiconductor layer 22 form a uniform type II heterostructure, serving as the channel layer 20.

[0080] C30, spin-coating photoresist on top of channel layer 20 (spin speed 2000 rpm~3000 rpm, spin coating time 40 s~60 s), pre-baking (90℃~100℃, time 10 s~60 s), then photolithography of a preset 6×6 array arrangement under ultraviolet light (10 s~60 s), development, and finally RIE treatment (carbon tetrafluoride gas treatment 10 s~60 s) and photoresist removal (acetone and isopropanol cleaning) to obtain the preset 6×6 array of channel layer 20.

[0081] C40, using a mask, deposits source / drain electrodes 30 on a 6×6 array of channel layer 20 to obtain a multi-band photoresponsive neural synapse device array based on a two-dimensional and organic heterostructure.

[0082] This embodiment also provides the application of the aforementioned multi-band optically responsive neural synaptic device array based on two-dimensional and organic heterostructures.

[0083] Among them, a multi-band photoresponsive neural synaptic device array based on a two-dimensional and organic heterostructure is used to perform parallel weight updates and / or signal processing on multiple multi-band optical pulses, thereby simulating the preprocessing function of the retina. The multi-band photoresponsive neural synaptic device array based on a two-dimensional and organic heterostructure is used to provide synchronous or asynchronous responses to multi-band optical pulses.

[0084] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. An application of a multi-band optically responsive neural synaptic device based on a two-dimensional and organic heterostructure in memory and brain-like learning, characterized in that, The multi-band photoresponsive neural synapse device based on a two-dimensional and organic heterostructure has a three-terminal bottom-gate top contact structure. It uses a band-matched two-dimensional material layer and an organic semiconductor layer to form a type II heterostructure as the channel layer. The two-dimensional material layer is a narrow bandgap two-dimensional material with a bandgap of less than 0.3 eV, and the organic semiconductor layer is made of DPP polymer. In this application, multi-band light pulses are used to simulate information input during the human brain's learning process, and the output current of the multi-band light-responsive neural synapse device based on a two-dimensional and organic heterostructure is used to simulate memory intensity during the human brain's learning process. Brain-like learning is achieved by applying / removing multi-band light pulses to the multi-band light-responsive neural synapse device based on a two-dimensional and organic heterostructure, and by using the multi-band light pulses and the output current to simulate the cognitive process of learning-forgetting-relearning in human memory. The multi-band optical pulses are far-infrared light of 8 μm to 14 μm and / or ultraviolet light of 315 nm to 400 nm.

2. The application of the multi-band optically responsive neural synapse device based on two-dimensional and organic heterostructures according to claim 1 in memory and brain-like learning, characterized in that: in, The multi-band optical pulses include optical pulses of different intensities, frequencies, frequencies, and durations.

3. The application of the multi-band optically responsive neural synaptic device based on a two-dimensional and organic heterostructure according to claim 1 or 2 in memory and brain-like learning, characterized in that, Includes the following steps: A10, Learning Phase: The multi-band light pulse is applied to the multi-band light-response neural synapse device based on two-dimensional and organic heterostructure to enhance its output current to a preset level, wherein the output current is used to simulate the memory intensity in the learning phase of cognitive behavior; A20, Forgetting Stage: Stop applying the multi-band light pulses, causing the output current to decay, thereby using the output current to simulate the memory strength in the forgetting stage of cognitive behavior; A30, Relearning Phase: The multi-band light pulse is applied again to the multi-band light-responsive neural synapse device based on a two-dimensional and organic heterostructure. In the relearning phase, the number of multi-band light pulses required to restore the output current to the preset level is less than the number of multi-band light pulses required for the learning phase, thereby using the output current to simulate the memory intensity of the relearning phase in cognitive behavior.

4. The application of the multi-band optically responsive neural synaptic device based on a two-dimensional and organic heterostructure as described in claim 1 in memory and brain-like learning. Its features are: The multi-band photoresponsive neural synapse device based on two-dimensional and organic heterostructure includes: Gate substrate; An insulating layer is disposed on the gate substrate; A channel layer, comprising the two-dimensional material layer and the organic semiconductor layer, wherein the two-dimensional material layer is disposed on the insulating layer, and the organic semiconductor layer is disposed on the two-dimensional material layer; and The source / drain electrodes are disposed on the organic semiconductor layer.

5. The application of the multi-band optically responsive neural synapse device based on two-dimensional and organic heterostructure according to claim 4 in memory and brain-like learning, characterized in that: in, The gate substrate comprises lightly, moderately, heavily, or extremely heavily p-type doped silicon wafers. The insulating layer is made of materials including SiO2, HfO2, ZrO2, or Al2O3. The source / drain materials include Au, Cr / Au, or Pt / Au.

6. The application of the multi-band optically responsive neural synapse device based on two-dimensional and organic heterostructure according to claim 4 in memory and brain-like learning, characterized in that: in, The material of the two-dimensional material layer includes tellurium, black phosphorus, bismuth telluride, molybdenum telluride, palladium diselenide, or platinum diselenide, and the thickness of the two-dimensional material layer is 10 nm to 50 nm. The DPP polymer includes PDPP4T, PDPP2T, DPP-TDTT, or DPP-PPV, and the thickness of the organic semiconductor layer is 20 nm to 80 nm.

7. The application of the multi-band optically responsive neural synaptic device based on a two-dimensional and organic heterostructure as described in claim 1 or 4 in memory and brain-like learning. Its features are: The fabrication method of the multi-band optically responsive neural synapse device based on two-dimensional and organic heterostructure includes the following steps: B10, a thin film of a uniform and continuous two-dimensional material with a band gap of less than 0.3 eV is prepared on a gate substrate with an insulating layer by chemical vapor deposition, as the two-dimensional material layer; B20, spin-coating or vapor-depositing the DPP polymer on the two-dimensional material layer and annealing to form a uniform type II heterostructure of two-dimensional material and organic semiconductor, as the channel layer; B30, source / drain electrodes are deposited on the channel layer to finally obtain the multi-band photoresponsive neural synapse device based on two-dimensional and organic heterostructure.

8. The application of the multi-band optically responsive neural synapse device based on two-dimensional and organic heterostructure according to claim 7 in memory and brain-like learning, characterized in that: in, In step B10, the deposition temperature is 5℃~15℃, and the deposition rate is 0.5 nm / min~5 nm / min. In step B20, the annealing temperature is 80 ℃~160 ℃, and the annealing time is 30 min~90 min.

9. An application of a multi-band optically responsive neural synaptic device array based on a two-dimensional and organic heterostructure, characterized in that, The array of multi-band photoresponsive neural synaptic devices based on two-dimensional and organic heterostructures includes several multi-band photoresponsive neural synaptic devices based on two-dimensional and organic heterostructures as described in any one of claims 1 to 8. The multi-band photoresponsive neural synapse device array based on a two-dimensional and organic heterostructure is used to perform parallel weight updates and / or signal processing on multiple multi-band light pulses, thereby simulating the preprocessing function of the retina. The array of multi-band optical responsive neural synaptic devices based on two-dimensional and organic heterostructures is used to respond synchronously or asynchronously to the multi-band optical pulses.

10. The application of the multi-band optically responsive neural synaptic device array based on a two-dimensional and organic heterostructure according to claim 9, characterized in that, The fabrication method of the multi-band optically responsive neural synaptic device array based on two-dimensional and organic heterostructure includes the following steps: B10, a thin film of a uniform and continuous two-dimensional material with a band gap of less than 0.3 eV is prepared on a gate substrate with an insulating layer by chemical vapor deposition, as the two-dimensional material layer; B20, spin-coating or vapor-depositing the DPP polymer on the two-dimensional material layer and annealing to form a uniform type II heterostructure of two-dimensional material and organic semiconductor, as the channel layer; C30, spin-coating photoresist over the channel layer, pre-baking and then photolithography and development under ultraviolet light to form a preset array, and finally obtaining the preset array of the channel layer through RIE processing and photoresist removal. C40, using a mask to deposit source / drain electrodes on the array of channel layers, to obtain the array of multi-band photoresponsive neural synaptic devices based on two-dimensional and organic heterostructures.

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