A multicolor optoelectronic response synaptic device and its preparation method

Abstract

The present invention discloses a multi-color optoelectronic response synaptic device and a preparation method thereof. The multi-color optoelectronic response synaptic device is a multi-layer structure. Along the light incident direction, the multi-layer structure successively includes a transparent conductive electrode layer, a hole transport material layer, a lead-free perovskite layer, an electron transport material layer, an organic semiconductor charge transfer complex layer, and a metal electrode layer. Preparation method: Prepare the transparent conductive electrode layer; successively prepare the hole transport material layer, the lead-free perovskite layer, the electron transport material layer, and the organic semiconductor charge transfer complex layer on the transparent conductive electrode layer by spin coating; vacuum deposit and prepare the metal electrode layer on the organic semiconductor charge transfer complex layer. The multi-color optoelectronic response synaptic device of the present invention has a reasonable structure design, can realize the simulation of multi-color optoelectronic synaptic functions in the ultraviolet-visible-near infrared range, and can realize the function of color recognition for red, green, and blue light in the visible light band, and has good application prospects.

Description

Technical Field

[0001] The present invention relates to the field of optoelectronic semiconductor technology, and relates to a multicolor optoelectronic response synaptic device and a preparation method thereof, and particularly relates to a multicolor optoelectronic response synaptic device based on lead-free perovskite and organic semiconductor and a preparation method thereof. Background Art

[0002] Neuromorphic devices based on artificial synapses integrate storage and computing units, providing an efficient and low-power solution for neuromorphic computing and promoting the development of intelligent hardware. Compared with neuromorphic devices regulated by electrical signals that have been widely studied, optoelectronic synaptic devices have significant advantages such as low crosstalk, strong anti-interference ability, and low power consumption. Multicolor optoelectronic response synapses can achieve optoelectronic responses in the ultraviolet-visible-near-infrared bands, broaden the light response range of the device, and improve its adaptability in various applications.

[0003] To achieve multicolor optoelectronic responses, materials such as organic semiconductor materials, perovskites, metal oxides, quantum dots, and two-dimensional materials have been widely used in the preparation of optoelectronic synapses. These materials have demonstrated their respective excellent properties and promoted the development of optoelectronic synaptic technology. Among these materials, organic semiconductor materials have received extensive attention due to their easy processing and adjustable structure, especially having obvious advantages in flexible electronic devices and low-cost manufacturing; perovskite materials have become a research hotspot due to their excellent light absorption ability and high photoelectric conversion efficiency. However, the environmental problems brought about by their potential lead toxicity still pose a major challenge restricting their applications. In addition, compared with the widely studied three-terminal transistor synapses, two-terminal structure synaptic devices can be prepared by a simple cross array method, which is convenient for high-density integration.

[0004] Therefore, it is of great practical significance to develop a multicolor optoelectronic response synaptic device that can achieve high-density integration and is environmentally friendly. Summary of the Invention

[0005] Due to the above-mentioned defects in the prior art, the present invention provides a multicolor optoelectronic response synaptic device that can achieve high-density integration and is environmentally friendly, specifically a multicolor optoelectronic response synaptic device based on lead-free perovskite and organic semiconductor that can be highly integrated, which overcomes the problem of environmental safety hazards existing in the perovskite materials used in current multicolor optoelectronic response synaptic devices.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A multicolor optoelectronic response synaptic device, which is a multilayer structure. The multilayer structure sequentially includes a transparent conductive electrode layer, a hole transport material layer, a lead-free perovskite layer, an electron transport material layer, an organic semiconductor charge transfer complex layer, and a metal electrode layer along the light incident direction;

[0008] The organic semiconductor donor molecule of the organic semiconductor charge transfer complex is a non-fullerene acceptor COTIC-4F, Y6 or IEICO-4F, the organic semiconductor acceptor molecule is PCE10, DPPDTT or PDPP4T, the mass ratio of the organic semiconductor donor molecule to the acceptor molecule is 2:1, and the total concentration is 12-18 mg / mL.

[0009] The above device is a vertical two-terminal device. The organic charge transfer complex layer is specifically a complex formed by the charge transfer of organic semiconductor donor molecules and acceptor molecules, and its light absorption band can be extended to the near-infrared band.

[0010] The transparent conductive electrode layer is used as an electrode to collect and transmit current; the hole transport material layer is used to transport the holes generated by the illumination of the lead-free perovskite layer; the electron transport material layer is used to transport the electrons generated by the illumination of the lead-free perovskite material layer and the organic semiconductor charge transfer complex layer; the metal electrode layer is a conductive metal; the photoactive layer is the lead-free perovskite layer and the organic semiconductor charge transfer complex layer. The lead-free perovskite has an absorption response to the ultraviolet-visible light band, and the organic semiconductor charge transfer complex has a significant absorption and response to light up to the near-infrared. Complementary absorption is formed between the two, broadening the spectral response range of the device. At the same time, the high exciton separation speed of the lead-free perovskite leads to the asymmetry of carrier transport, providing a physical basis for synaptic plasticity simulation. In addition, due to the self-filtering effect of the lead-free perovskite, the intensity of long-wavelength light entering the organic semiconductor layer can be weakened, enhancing the difference in photoelectric responses in different bands, thus supporting color recognition and spectral information processing in neuromorphic computing. This multi-layer collaborative design realizes the simulation of synaptic functions required by the human visual system, demonstrating potential application value in the field of optoelectronic neural computing.

[0011] The multi-color optoelectronic response synaptic device of the present invention has a reasonable structural design. It can realize the simulation of multi-color optoelectronic synaptic functions in the ultraviolet-visible-near-infrared range, and can realize the function of color recognition for red, green, and blue light in the visible light band; compared with previous optoelectronic synaptic response devices, it has the advantages of multi-color response, color recognition, environmental friendliness and easy integration, and has great application prospects.

[0012] As a preferred technical solution:

[0013] For a multi-color optoelectronic response synaptic device as described above, the transparent conductive electrode layer is FTO conductive glass or ITO conductive glass.

[0014] For a multi-color optoelectronic response synaptic device as described above, the hole transport material layer is a P-type semiconductor material insoluble in DMF and DMSO solvents.

[0015] A multi - color optoelectronic response synaptic device as described above, wherein the hole - transporting material layer is PEDOT:PSS, PTAA or CuSCN.

[0016] A multi - color optoelectronic response synaptic device as described above, wherein the lead - free perovskite layer is a non - toxic bismuth - based perovskite CsBi3I that absorbs ultraviolet - visible light and is environmentally friendly 10 , CsAgBiBr6 or CsBi3Br 10 .

[0017] A multi - color optoelectronic response synaptic device as described above, wherein the electron - transporting material layer is an N - type semiconductor material that is insoluble in chlorobenzene or chloroform.

[0018] A multi - color optoelectronic response synaptic device as described above, wherein the electron - transporting material layer is PDINO, PDINN or PFN - Br.

[0019] A multi - color optoelectronic response synaptic device as described above, wherein the metal electrode layer is Au, Ag or Al.

[0020] In addition, the present invention also provides a preparation method of a multi - color optoelectronic response synaptic device as described above, comprising the following steps:

[0021] (1) Prepare a transparent conductive electrode layer;

[0022] (2) On the transparent conductive electrode layer prepared in step S1, sequentially prepare a hole - transporting material layer, a lead - free perovskite layer, an electron - transporting material layer and an organic semiconductor charge - transfer complex layer by spin - coating;

[0023] (3) Vacuum deposit a metal electrode layer on the organic semiconductor charge - transfer complex layer.

[0024] The above - mentioned method is simple to operate, low in cost and has good application prospects.

[0025] The above - mentioned technical solutions are only one feasible technical solution of the present invention, and the protection scope of the present invention is not limited thereto. Those skilled in the art can reasonably adjust the specific design according to actual needs.

[0026] The above - mentioned invention has the following advantages or beneficial effects:

[0027] (1) The multi - color optoelectronic response synaptic device of the present invention has a reasonable structural design, can realize the simulation of multi - color optoelectronic synaptic functions in the ultraviolet - visible - near - infrared range, and can realize the function of color recognition for red, green and blue light in the visible light band;

[0028] (2) The multi - color optoelectronic response synaptic device of the present invention has the advantages of multi - color response, color recognition, environmental friendliness and easy integration compared with the previous optoelectronic synaptic response devices;

[0029] (3)The preparation method of the multicolor optoelectronic response synaptic device of the present invention is simple to operate, low in cost, and has good application prospects. Description of the Drawings

[0030] By reading the following detailed description of the non-limiting embodiments with reference to the accompanying drawings, the present invention and its features, shapes, and advantages will become more obvious. The same reference numerals indicate the same parts in all the drawings. The drawings are not drawn to scale, and the emphasis is on showing the gist of the present invention.

[0031] Figure 1 Schematic structural diagram of the multicolor optoelectronic response synaptic device of the present invention;

[0032] Figure 2 Flow chart of the preparation method of the multicolor optoelectronic response synaptic device of the present invention;

[0033] Figure 3 Comparison diagram of ultraviolet-visible-near-infrared absorption spectra of materials of lead-free perovskite, organic semiconductor charge transfer complex, and composite lead-free perovskite and organic semiconductor charge transfer complex;

[0034] Figure 4 Excitatory postsynaptic current of the multicolor optoelectronic response synaptic device of the present invention under two consecutive identical ultraviolet light (a) and infrared light (b) pulses;

[0035] Figure 5 Schematic diagram of the paired-pulse facilitation index of the multicolor optoelectronic response synaptic device of the present invention under ultraviolet light (c) and infrared light (d);

[0036] Figure 6 Current-voltage curves of the multicolor optoelectronic response synaptic device of the present invention in the dark and under red light (700 nm, 1 mW cm -2 ), green light (500 nm, 1 mW cm -2 ), and blue light (405 nm, 1 mW cm -2 );

[0037] Figure 7 Excitatory postsynaptic current triggered by 50 identical pulses (0.5 s light illumination time, 0.5 s interval time) of the multicolor optoelectronic response synaptic device of the present invention under red light (700 nm, 1 mW cm -2 ), green light (500 nm, 1 mW cm -2 ), and blue light (405 nm, 1 mW cm -2 );

[0038] Figure 8Time-current curves of Comparative Example 1 under different bias voltages;

[0039] Figure 9 Time-current curves of Comparative Example 2 under different bias voltages. Detailed implementation mode

[0040] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but it is not a limitation of the present invention.

[0041] Example 1

[0042] A multicolor optoelectronic response synaptic device, the structure of which is as Figure 1 shown, where the transparent conductive electrode selects ITO, the hole transport material selects PEDOT:PSS, the lead-free perovskite selects CsBi3I 10 , the electron transport material selects PDINO, the organic semiconductor charge transfer complex selects PCE10 and COTIC-4F, and the metal electrode selects gold.

[0043] Its preparation method is as Figure 2 shown, specifically:

[0044] Step S1, ultrasonically clean the ITO substrate with acetone, ultrapure water, and isopropanol for 15 min respectively, then dry the surface of the ITO substrate with nitrogen, and then treat the ITO substrate in a plasma cleaner for 15 min for standby.

[0045] Step S2, mix PEDOT:PSS and ultrapure water in a volume ratio of 1:1 and stir evenly, then spin-coat on ITO, spin-coat at 4000 rpm for 60 s, and anneal at 150 °C for 30 min to obtain a hole transport material layer; dissolve 445 mg of BiI3 and 195 mg of CsI in 0.8 mL of DMF and 0.2 mL of DMSO, stir at 60 °C for 3 h for standby, then spin-coat on the hole transport material layer, spin-coat at 5000 rpm for 10 s, spin-coat at 3500 rpm for 40 s, add 0.3 mL of anti-solvent chlorobenzene 28 s after the end of spin-coating, and anneal at 125 °C for 30 min; dissolve 1 mg of PDINO in 1 mL of isopropanol, stir at room temperature for 1 h to dissolve, then spin-coat on the perovskite layer, spin-coat at 4000 rpm for 25 s, and anneal at 100 °C for 5 min to obtain an electron transport material layer; dissolve 5 mg of PCE10 and 10 mg of COTIC-4F in 1 mL of chloroform and 5 μL of 1-chloronaphthalene, stir at 60 °C for 12 h, then spin-coat on PDINO, spin-coat at 2000 rpm for 60 s, and anneal at 110 °C for 10 min to obtain an organic semiconductor charge transfer complex material layer.

[0046] Step S3, by means of a mask, deposit a 30-nm-thick gold electrode onto the organic semiconductor charge transfer complex material layer under a high vacuum of 1×10 -3 Pa to obtain a metal electrode layer, that is, the multicolor optoelectronic response synaptic device shown as Figure 1 is fabricated.

[0047] Perform absorption spectrum tests on the materials of lead-free perovskite CsBi3I 10 , organic semiconductor charge transfer complex PCE10:COTIC-4F, composite lead-free perovskite CsBi3I 10 and organic semiconductor charge transfer complex PCE10:COTIC-4F respectively. The test results are as shown in Figure 3 . It can be seen from Figure 3 that CsBi3I 10 absorbs ultraviolet and visible light, PCE10:COTIC-4F absorbs ultraviolet, visible, and near-infrared light, and the materials of composite lead-free perovskite CsBi3I 10 and organic semiconductor charge transfer complex PCE10:COTIC-4F absorb ultraviolet, visible, and near-infrared light. Moreover, due to the absorption of ultraviolet and visible light by perovskite CsBi3I 10 , the absorption of the composite film for visible light is enhanced.

[0048] Perform performance tests on the above-mentioned multicolor optoelectronic response synaptic device. The specific tests are as follows: Under room temperature and atmospheric environment, use a Keithley 4200 semiconductor parameter analyzer and a probe station to conduct response tests; the light source uses a xenon lamp light source and an optical shutter to provide specific wavelengths and pulses; the test content: conduct synaptic performance tests under ultraviolet, visible, and near-infrared light to simulate excitatory postsynaptic current and paired-pulse facilitation. The test results are as shown in Figures 4 to 7 .

[0049] It can be seen from Figures 4 to 5 that the multicolor optoelectronic response synaptic device can realize the behavior simulation of excitatory postsynaptic current and paired-pulse facilitation under ultraviolet and infrared light;

[0050] It can be seen from Figures 6 to 7 that the response currents of the multicolor optoelectronic response synaptic device under red, green, and blue light are quite different, and it can realize color recognition in the visible light band.

[0051] Comparative Example 1

[0052] An optoelectronic device has a structure basically the same as that of Example 1, except that there is no organic semiconductor charge transfer complex material layer. Its preparation method is basically the same as that of Example 1, except that the preparation step of the organic semiconductor charge transfer complex material layer is absent.

[0053] The performance of the above optoelectronic device was tested. Figure 8 Fig. is the time-current curve of Comparative Example 1 under different bias voltages. It can be seen from Figure 8 that the device is a photodetector under different bias voltages and cannot achieve a photoelectric response synapse.

[0054] Comparative Example 2

[0055] An optoelectronic device has a structure basically the same as that of Example 1, except that there is no lead-free perovskite layer. Its preparation method is basically the same as that of Example 1, except that the preparation step of the lead-free perovskite layer is absent.

[0056] The performance of the above optoelectronic device was tested. Figure 9 Fig. is the time-current curve of Comparative Example 2 under different bias voltages. It can be seen from Figure 9 that the device is a photodetector under different bias voltages and cannot achieve a photoelectric response synapse.

[0057] Those skilled in the art should understand that those skilled in the art can implement variations in combination with the prior art and the above embodiments, which will not be elaborated here. Such variations do not affect the essence of the present invention and will not be elaborated here.

[0058] The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments. The devices and structures not described in detail should be understood to be implemented in a common manner in the art; any person skilled in the art can make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment with equivalent changes, without departing from the scope of the technical solution of the present invention, which does not affect the essence of the present invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the protection of the technical solution of the present invention.

Claims

1. A multicolor optoelectronic response synaptic device, characterized in that, It is a multi-layer structure, and the multi-layer structure is, in the light incident direction, successively a transparent conductive electrode layer, a hole transport material layer, a lead-free perovskite layer, an electron transport material layer, an organic semiconductor charge transfer complex layer, and a metal electrode layer; The organic semiconductor acceptor molecule of the organic semiconductor charge transfer complex is COTIC-4F, Y6 or IEICO-4F, the organic semiconductor donor molecule is PCE10, DPPDTT or PDPP4T, the mass ratio of the organic semiconductor acceptor molecule to the donor molecule is 2:1, and the total concentration is 12-18 mg / mL.

2. The multicolor optoelectronic response synaptic device according to claim 1, characterized in that, The transparent conductive electrode layer is FTO conductive glass or ITO conductive glass.

3. The multicolor optoelectronic response synaptic device according to claim 1, characterized in that, The hole transport material layer is a P-type semiconductor material insoluble in DMF and DMSO solvents.

4. A multi-color optoelectronic response synaptic device according to claim 3, wherein, The hole transport material layer is PEDOT:PSS, PTAA or CuSCN.

5. A multi-color optoelectronic response synaptic device according to claim 1, characterized in that, The lead-free perovskite layer is a bismuth-based perovskite CsBi3I 10 , CsAgBiBr6 or CsBi3Br 10 .

6. The multicolor optoelectronic response synaptic device according to claim 1, characterized in that, The electron transport material layer is an N-type semiconductor material insoluble in chlorobenzene or chloroform.

7. A multicolor optoelectronic response synaptic device according to claim 6, characterized in that, The electron transport material layer is PDINO, PDINN or PFN-Br.

8. The multicolor optoelectronic response synaptic device according to claim 1, characterized in that The metal electrode layer is Au, Ag or Al.

9. A method for preparing a multi-color optoelectronic response synaptic device according to any one of claims 1 to 8, characterized in that, It includes the following steps: (1) Prepare the transparent conductive electrode layer; (2) On the transparent conductive electrode layer prepared in step S1, successively prepare a hole transport material layer, a lead-free perovskite layer, an electron transport material layer, and an organic semiconductor charge transfer complex layer by spin coating; (3) Vacuum deposit and prepare a metal electrode layer on the organic semiconductor charge transfer complex layer.

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