Multicolor photoelectric response synaptic device and preparation method thereof

Abstract

The invention discloses a multicolor photoelectric response synaptic device and a preparation method thereof. The multicolor photoelectric response synaptic device is of a multi-layer structure. The multilayer structure comprises 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 compound layer and a metal electrode layer in sequence along the light incidence direction. The preparation method comprises the steps of preparing the transparent conductive electrode layer; sequentially preparing a hole transport material layer, a lead-free perovskite layer, an electron transport material layer and an organic semiconductor charge transfer compound layer on the transparent conductive electrode layer through a spin coating method; and preparing the metal electrode layer on the organic semiconductor charge transfer compound layer through vacuum evaporation. The multicolor photoelectric response synaptic device is reasonable in structural design, can realize ultraviolet-visible-near infrared multicolor photoelectric synaptic function simulation, can realize a color identification function on red light, green light and blue light in a visible light wave band, and has a good application prospect.

Description

Technical Field

[0001] The present invention relates to the field of optoelectronic semiconductor technology, and in particular to a multicolor photoelectric 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 efficient and low-energy solutions for neuromorphic computing and promoting the development of intelligent hardware. Compared with neuromorphic devices controlled by electrical signals that have been widely studied, optoelectronic synaptic devices have significant advantages such as low crosstalk, strong anti-interference and low power consumption. Multicolor photoelectric response synapses can achieve photoelectric response in the ultraviolet-visible-near infrared band, broaden the light response range of the device, and improve its adaptability in a variety of applications.

[0003] In order to achieve multicolor photoelectric response, materials such as organic semiconductors, perovskites, metal oxides, quantum dots and two-dimensional materials are widely used in the preparation of photoelectric synapses. These materials have demonstrated their own excellent performance and promoted the development of photoelectric synapse technology. Among these materials, organic semiconductor materials have attracted widespread attention due to their easy processing and structural adjustability, especially 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 caused by their potential lead toxicity are still a major challenge restricting their application. In addition, compared with the widely studied three-terminal transistor synapses, the two-terminal structured 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 multi-color photoelectric 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 multi-color photoelectric response synaptic device that can achieve high-density integration and is environmentally friendly, specifically a multi-color photoelectric response synaptic device based on lead-free perovskite and organic semiconductors that can be integrated with high density, which overcomes the environmental safety hazard of perovskite materials used in current multi-color photoelectric response synaptic devices.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A multicolor photoelectric response synaptic device is a multi-layer structure, wherein the multi-layer structure is 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 in sequence along the incident direction of light; 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.

[0008] The above device is a two-terminal device with a vertical structure. The organic charge transfer complex layer is specifically a complex formed by organic semiconductor donor molecules and acceptor molecules through charge transfer, and its absorption band can be extended to the near-infrared band.

[0009] The transparent conductive electrode layer is used as an electrode to collect and transmit current; the hole transport material layer is used to transport holes generated by the lead-free perovskite layer under illumination; the electron transport material layer is used to transport electrons generated by the lead-free perovskite material layer and the organic semiconductor charge transfer complex layer under illumination; the metal electrode layer is a conductive metal; the photoactive layer is a lead-free perovskite layer and an organic semiconductor charge transfer complex layer. The lead-free perovskite has an absorption response to the ultraviolet and visible light bands, and the organic semiconductor charge transfer complex has significant absorption and response to light to the near-infrared. The two form complementary absorption, which broadens 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 transmission, providing a physical basis for the simulation of synaptic plasticity. In addition, the self-filtering effect of the lead-free perovskite can weaken the intensity of long-wavelength light entering the organic semiconductor layer, so that the difference in photoelectric response in different bands is enhanced, thereby 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 and demonstrates its potential application value in the field of optoelectronic neural computing.

[0010] The multicolor photoelectric response synapse device of the present invention has a reasonable structural design. It can realize the simulation of multicolor photoelectric synapse functions in the ultraviolet-visible-near infrared range, and can realize the color recognition function for red, green and blue lights in the visible light band. Compared with previous photoelectric synapse response devices, it has the advantages of multicolor response, color recognition, environmental friendliness and easy integration, and has great application prospects.

[0011] As the preferred technical solution:

[0012] In the multicolor photoelectric response synaptic device as described above, the transparent conductive electrode layer is FTO conductive glass or ITO conductive glass.

[0013] In the multicolor photoelectric response synaptic device as described above, the hole transport material layer is a P-type semiconductor material that is insoluble in DMF and DMSO solvents.

[0014] In the multicolor photoelectric response synaptic device as described above, the hole transport material layer is PEDOT:PSS, PTAA or CuSCN.

[0015] A multicolor photoelectric response synaptic device as described above, wherein the lead-free perovskite layer is a non-toxic bismuth-based perovskite CsBi that absorbs ultraviolet-visible light and is environmentally friendly. 3 I 10 、CsAgBiBr 6 or CsBi 3 Br 10 .

[0016] In the multicolor photoelectric response synaptic device as described above, the electron transport material layer is an N-type semiconductor material that is insoluble in chlorobenzene or chloroform.

[0017] In the multicolor photoelectric response synaptic device as described above, the electron transport material layer is PDINO, PDINN or PFN-Br.

[0018] In the multicolor photoelectric response synaptic device as described above, the metal electrode layer is Au, Ag or Al.

[0019] In addition, the present invention also provides a method for preparing the multicolor photoelectric response synaptic device as described above, comprising the following steps:

[0020] (1) Preparing a transparent conductive electrode layer;

[0021] (2) preparing a hole transport material layer, a lead-free perovskite layer, an electron transport material layer and an organic semiconductor charge transfer complex layer in sequence by spin coating the transparent conductive electrode layer prepared in step S1;

[0022] (3) Preparing a metal electrode layer by vacuum evaporation on the organic semiconductor charge transfer complex layer.

[0023] The above method is easy to operate, low in cost and has good application prospects.

[0024] The above technical solution is only a 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.

[0025] The above invention has the following advantages or beneficial effects:

[0026] (1) The multicolor photoelectric response synaptic device of the present invention has a reasonable structural design, which can realize the simulation of the multicolor photoelectric synaptic function of ultraviolet-visible-near infrared, and can realize the color recognition function of red, green and blue light in the visible light band;

[0027] (2) Compared with the previous photoelectric synaptic response devices, the multi-color photoelectric response synaptic device of the present invention has the advantages of multi-color response, color recognition, environmental friendliness and easy integration;

[0028] (3) The preparation method of the multicolor photoelectric response synaptic device of the present invention is simple to operate, low in cost and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention and its features, appearance and advantages will become more apparent by reading the detailed description of non-limiting embodiments with reference to the following drawings. The same reference numerals indicate the same parts in all the drawings. The drawings are not drawn to scale, and emphasis is placed on illustrating the subject matter of the present invention.

[0030] Figure 1 It is a schematic structural diagram of the multicolor photoelectric response synaptic device of the present invention;

[0031] Figure 2 A flow chart of a method for preparing a multicolor photoelectric response synaptic device of the present invention;

[0032] Figure 3 A comparison diagram of UV-visible-near infrared absorption spectra of lead-free perovskite, organic semiconductor charge transfer complex and composite lead-free perovskite and organic semiconductor charge transfer complex;

[0033] Figure 4 The excitatory postsynaptic current of the multicolor photoelectric response synaptic device of the present invention under two consecutive identical ultraviolet light (a) and infrared light (b) pulses;

[0034] Figure 5 Schematic diagram of double pulse facilitation index of the multicolor photoelectric response synaptic device of the present invention under ultraviolet light (c) and infrared light (d);

[0035] Figure 6 The multicolor photoelectric responsive synaptic device of the present invention is responsive to light 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 )under the current-voltage curve;

[0036] Figure 7 The multicolor photoelectric responsive synaptic device of the present invention is subjected to 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) under 50 identical pulses (0.5 s light duration, 0.5 s interval) triggered excitatory postsynaptic currents;

[0037] Figure 8 The time-current curves of comparative example 1 under different bias voltages;

[0038] Fig. 9 The time-current curves of comparative example 2 under different bias voltages. DETAILED DESCRIPTION

[0039] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0040] Example 1

[0041] A multicolor photoelectric response synaptic device, the structure of which is as follows Figure 1 As shown, the transparent conductive electrode is ITO, the hole transport material is PEDOT:PSS, and the lead-free perovskite is CsBi 3 I 10 , PDINO is used as the electron transport material, PCE10 and COTIC-4F are used as the organic semiconductor charge transfer complex, and gold is used as the metal electrode.

[0042] Its preparation method is as follows Figure 2 As shown, specifically:

[0043] Step S1, using acetone, ultrapure water, and isopropanol to ultrasonically clean the ITO substrate for 15 minutes respectively, then blowing the surface of the ITO substrate dry with nitrogen, and then treating the ITO substrate in a plasma cleaning machine for 15 minutes for later use.

[0044] Step S2, PEDOT:PSS and ultrapure water were mixed and stirred in a volume ratio of 1:1, and then spin-coated on ITO at 4000 rpm for 60 s and annealed at 150 °C for 30 min to obtain a hole transport material layer; 445 mg BiI 3195 mgCsI was dissolved in 0.8 mL DMF and 0.2 mL DMSO, stirred at 60 °C for 3 h, and then spin-coated on the hole transport material layer at 5000 rpm for 10 s and 3500 rpm for 40 s. 0.3 mL of anti-solvent chlorobenzene was added 28 s after the end of spin coating, and annealed at 125 °C for 30 min. 1 mg PDINO was dissolved in 1 mL isopropanol, stirred at room temperature for 1 h to dissolve, and then spin-coated on the perovskite layer at 4000 rpm for 25 s, annealed at 100 °C for 5 min to obtain the electron transport material layer. 5 mgPCE10 and 10 mg COTIC-4F were dissolved in 1 mL chloroform and 5 μL 1-chloronaphthalene, stirred at 60 °C for 12 h, and then spin-coated on PDINO at 2000 rpm for 60 s, annealed at 110 °C for 10 min, to obtain an organic semiconductor charge transfer complex material layer.

[0045] Step S3, by means of a mask, in a high vacuum of 1×10 -3 A 30 nm thick gold electrode was evaporated onto the organic semiconductor charge transfer complex material layer at 100 Pa to obtain a metal electrode layer, that is, Figure 1 The multicolor photoelectrically responsive synaptic device shown.

[0046] Lead-free perovskite CsBi 3 I 10 、Organic semiconductor charge transfer complex PCE10:COTIC-4F、Composite lead-free perovskite CsBi 3 I 10 The absorption spectra of PCE10:COTIC-4F and organic semiconductor charge transfer complex were tested respectively. The test results are as follows: Figure 3 As shown, from Figure 3 It can be seen that CsBi 3 I 10 It absorbs ultraviolet and visible light. PCE10:COTIC-4F absorbs ultraviolet, visible and near-infrared light. The composite lead-free perovskite CsBi 3 I 10 The materials of PCE10:COTIC-4F and organic semiconductor charge transfer complex absorb ultraviolet, visible and near-infrared light, and because the perovskite CsBi 3 I 10 Absorption of ultraviolet and visible light: the composite film has enhanced absorption of visible light.

[0047] The performance test of the above multi-color photoelectric response synaptic device is carried out. The specific test is as follows: in the room temperature atmosphere, the response test is carried out using the Keithley 4200 semiconductor parameter analyzer and the probe station; the light source uses a xenon light source and an optical shutter to provide a specific wavelength and pulse; the test content: the synaptic performance test is carried out under ultraviolet light, visible light and near-infrared light to simulate the excitatory postsynaptic current and double pulse facilitation. The test results are as follows Figures 4 to 7 shown.

[0048] from Figures 4 and 5 It can be seen that the multicolor photoelectric response synaptic device can realize the behavioral simulation of excitatory postsynaptic current and double pulse facilitation under ultraviolet and infrared light;

[0049] from Figures 6 and 7 It can be seen that the response current of the multi-color photoelectric response synaptic device under red, green and blue light is quite different, which can realize color recognition in the visible light band.

[0050] Comparative Example 1

[0051] A photoelectric device, whose structure is basically the same as that of Example 1, except that there is no organic semiconductor charge transfer complex material layer; and whose preparation method is basically the same as that of Example 1, except that there is no organic semiconductor charge transfer complex material layer preparation step.

[0052] The above-mentioned optoelectronic devices are subjected to performance tests. Figure 8 The time-current curves of comparative example 1 under different bias voltages are shown in FIG. Figure 8 It can be seen that the devices are all photodetectors under different bias voltages and cannot achieve photoelectric response synapses.

[0053] Comparative Example 2

[0054] A photoelectric device, whose structure is basically the same as that of Example 1, except that there is no lead-free perovskite layer, and whose preparation method is basically the same as that of Example 1, except that there is no step of preparing the lead-free perovskite layer.

[0055] The above-mentioned optoelectronic devices are subjected to performance tests. Fig. 9 The time-current curves of comparative example 2 under different bias voltages are shown in FIG. Fig. 9 It can be seen that the devices are all photodetectors under different bias voltages and cannot achieve photoelectric response synapses.

[0056] Those skilled in the art should understand that those skilled in the art can implement variations by combining the prior art and the above embodiments, which will not be described in detail here. Such variations do not affect the essential content of the present invention, and will not be described in detail here.

[0057] The above describes the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the above-mentioned specific embodiments, and the devices and structures that are not described in detail should be understood to be implemented in a common manner in the art; any technician familiar with the art can use the above-disclosed methods and technical contents to make many possible changes and modifications to the technical solutions of the present invention without departing from the scope of the technical solutions of the present invention, or modify them into equivalent embodiments of equivalent changes, which does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention are still within the scope of protection of the technical solutions of the present invention.

Claims

1. A multicolor photoelectric response synaptic device, characterized in that: It is a multi-layer structure, which is 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 in sequence along the incident direction of light; The organic semiconductor donor molecule of the organic semiconductor charge transfer complex is 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.

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

3. A multicolor photoelectric 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 multicolor photoelectric response synaptic device according to claim 3, characterized in that: The hole transport material layer is PEDOT:PSS, PTAA or CuSCN.

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

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

8. The multicolor photoelectric 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 multicolor photoelectric response synaptic device according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) Preparing a transparent conductive electrode layer; (2) preparing a hole transport material layer, a lead-free perovskite layer, an electron transport material layer and an organic semiconductor charge transfer complex layer in sequence by spin coating the transparent conductive electrode layer prepared in step S1; (3) Preparing a metal electrode layer by vacuum evaporation on the organic semiconductor charge transfer complex layer.

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