Preparation method of high-stability heterojunction material memristor

Abstract

The invention belongs to the technical field of memristors, and particularly relates to a preparation method of a high-stability heterojunction material memristor, and the method comprises the following steps: S1, making a sample, and employing a conductive material as a substrate and a bottom electrode; s2, preparing a Cs3Bi2Br9 solution, and preparing the Cs3Bi2Br9 solution by mixing CsBr powder, BiBr3 powder, DMSO (Dimethylsulfoxide) and DMF (Dimethyl Formamide); s3, mixing and stirring the Cs3Bi2Br9 solution in the S2, adding HBr after 1 hour, and then continuously stirring and mixing; s4, performing plasma treatment on the sample in the S1, and spin-coating the sample with a Cs3Bi2Br9 solution; s5, sputtering a ZnO thin film on the sample subjected to spin coating in the step S4 for end sealing; s6, plating a top electrode on the sample subjected to ZnO film end sealing; by using the ZnO thin film to seal the end, the challenge brought by the traditional solution method for constructing the active layer of the perovskite memristor at present can be overcome, the preparation repetition rate of the memristor is effectively improved, the stability of the perovskite and the reliability of the device are effectively improved, and the problem that the stability of the existing preparation method of the perovskite thin film memristor is relatively poor is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of memristors, and in particular relates to a method for preparing a high-stability heterojunction material memristor. Background Art

[0002] Cs3Bi2Br9 is a lead-free perovskite material that has attracted much attention for its green, non-toxic and excellent performance. This material has outstanding performance in the fields of X-ray detectors, sensors, optoelectronic devices, etc., and is also widely used in the construction of memristors.

[0003] At present, halide perovskites need to improve not only electrical properties in practical applications, but also solve the problem of degradation caused by water, oxygen, light, heat, etc. in the environment. Among them, the use of low-dimensional halide perovskites is one of the effective means to solve this problem. This method is often used in related two-dimensional halide perovskite-based memristors such as Cs3Bi2Br9, CsPbI3, and MAPbI3. However, due to the difficulty in preparing halide perovskite films with good uniformity and high density by traditional solution methods, and the complex factors such as environmental temperature and humidity, material defects, and ion migration, the memristors prepared by this method have low repeatability and the reliability of the device cannot be guaranteed. Experimental analysis has concluded that the poor uniformity and density of Cs3Bi2Br9 films prepared by traditional solution methods lead to low repetition rate and poor stability of the device. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a high-stability heterojunction material memristor, and to solve the problem of poor stability of the existing perovskite thin film memristor preparation method by using oxide layer capping.

[0005] In order to achieve the above technical objectives, the technical solution adopted by the present invention is as follows:

[0006] Using a conductive material as a substrate and a bottom electrode and preparing a sample;

[0007] Cs3Bi2Br9 solution was prepared based on CsBr and BiBr3 powders and a mixture of DMSO and DMF as solvent;

[0008] Add a small amount of HBr to the Cs3Bi2Br9 solution after stirring for 1 hour and continue stirring;

[0009] The plasma treated sample was spin coated with Cs3Bi2Br9 solution, anti-solvent was added during the spin coating process, and annealing was performed;

[0010] A ZnO film was sputtered on the sample after spin coating of Cs3Bi2Br9 by a magnetron sputtering instrument for termination;

[0011] The top electrode was plated on the sample after ZnO film termination by magnetron sputtering.

[0012] Among them, in "using conductive materials as substrates and bottom electrodes and preparing samples", the conductive materials are ITO, FTO, and Si, and the sample preparation includes cutting and ultrasonic cleaning, and the ultrasonic cleaning includes ultrasonication in acetone, anhydrous ethanol, and deionized water for 20-30 minutes in sequence.

[0013] Among them, in the "preparation of Cs3Bi2Br9 solution based on CsBr and BiBr3 powders and a mixture of DMSO and DMF as solvent", the configuration parameters of the Cs3Bi2Br9 solution are stirring for 2-3 hours at a speed of 500-700 rpm / min and a temperature of 60-70°C, the molar ratio of CsBr and BiBr3 powders is 3:2, and the molar ratio of DMSO and DMF is 1:(4-9).

[0014] Among them, in “adding a trace amount of HBr to the Cs3Bi2Br9 solution after stirring for 1 hour and continuing to stir”, the concentration of HBr is 48%, and the volume ratio of HBr to Cs3Bi2Br9 solution is 1:200.

[0015] Among them, in "spin coating the plasma-treated sample with Cs3Bi2Br99 solution, adding an anti-solvent during the spin coating process, and performing annealing treatment", the plasma treatment is a treatment in a plasma cleaner for 5-10 minutes; the parameters for spin coating of the Cs3Bi2Br9 solution are a high speed of 4000-5000rpm / min and a time of 40-50s; the anti-solvent is toluene or chlorobenzene, and the adding time is 15-20s after the start of spin coating; the annealing treatment parameters are 100-120°C and a time of 10-15min.

[0016] Among them, in "sputtering ZnO film on the sample after spin coating Cs3Bi2Br9 by magnetron sputtering for termination", the parameters of the magnetron sputtering ZnO film are sputtering gas pressure 0.4-0.6Pa, sputtering Ar gas flow rate 30-40sccm, sputtering power 80-90W, and sputtering time 12-15min.

[0017] Wherein, in “plating a top electrode on the sample after ZnO film termination by magnetron sputtering”, the magnetron sputtering top electrode is Ag, Al, Au or ITO.

[0018] The present invention utilizes ZnO thin film capping to help overcome the challenges brought by the current traditional solution method for constructing the active layer of perovskite memristor, effectively improve the repetition rate of memristor preparation, and effectively improve the stability of perovskite and device reliability, thereby solving the problem of poor stability of existing perovskite thin film memristor preparation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention is further illustrated by means of the non-limiting examples given in the accompanying drawings.

[0020] Figure 1 The present invention provides a flow chart of a method for preparing a high-stability oxide-capped perovskite material memristor.

[0021] Figure 2 It is a schematic diagram of the preparation process of composite thin film memristor.

[0022] Figure 3 This is a schematic diagram of the ITO / Cs3Bi2Br9 / ZnO / Ag memristor structure.

[0023] Figure 4 This is the IV curve of ITO / Cs3Bi2Br9 / ZnO / Ag memristor. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the present invention, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0025] Example 1: Figure 1-4 As shown, a method for preparing a high-stability heterojunction material memristor of the present invention comprises:

[0026] S1 uses a conductive material as a substrate and a bottom electrode and prepares a sample;

[0027] The conductive materials are ITO, FTO, and Si. The sample preparation includes cutting and ultrasonic cleaning. The ultrasonic cleaning includes ultrasonication in acetone, anhydrous ethanol, and deionized water for 20-30 minutes in sequence.

[0028] Specifically, ITO, FTO glass or Si wafer with conductive ability is prepared as the bottom electrode and substrate, cut into suitable sizes, and ultrasonicated in acetone, anhydrous ethanol and deionized water for 20-30 minutes in sequence.

[0029] S2 prepares Cs3Bi2Br9 solution based on CsBr and BiBr3 powders and a mixture of DMSO and DMF as solvent;

[0030] Specifically, the corresponding weights of CsBr and BiBr3 powders are weighed on a balance and placed in a glass container, and the molar ratio of CsBr to BiBr3 powders is 3:2. DMSO and DMF are added to the container containing the above two powders in a molar ratio of 1:(4-9), and a magnetic stirrer is added, and the Cs3Bi2Br9 solution is prepared by stirring at a speed of 500-700 rpm / min and a temperature of 60-70°C for 2-3 hours.

[0031] S3 added a small amount of HBr to the mixture after stirring for 1 h and continued stirring;

[0032] Specifically, after 1 hour, a small amount of HBr is added to the Cs3Bi2Br9 solution prepared in step S2, the concentration of HBr is 48%, and the volume ratio of HBr to Cs3Bi2Br9 solution is 1:200.

[0033] S4 spin-coating the plasma-treated sample with a Cs3Bi2Br9 solution, dropping an anti-solvent during the spin-coating process, and performing an annealing treatment;

[0034] Specifically, the sample treated in step S1 is treated in a plasma cleaning machine for 5-10 minutes, and then Cs3Bi2Br9 is spin-coated on the plasma-treated sample. The parameters for Cs3Bi2Br9 spin coating are high speed 4000-5000rpm / min and time 40-50s; the anti-solvent is toluene or chlorobenzene, and the dripping time is 15-20s after the start of spin coating; the annealing treatment parameters are 100-120°C and time 10-15min.

[0035] S5 uses a magnetron sputtering instrument to sputter ZnO thin film on the sample after spin coating of Cs3Bi2Br9 for termination;

[0036] Specifically, the sample processed in step S4 is terminated by magnetron sputtering ZnO thin film, and the parameters of magnetron sputtering ZnO are sputtering gas pressure 0.4-0.6 Pa, sputtering Ar gas flow rate 30-40 sccm, sputtering power 80-90 W, and sputtering time 12-15 min.

[0037] S6: using magnetron sputtering to plate the top electrode on the sample after ZnO film termination;

[0038] Specifically, a mask is attached to the surface of the sample processed in step S5, and a top electrode is plated by a magnetron sputtering apparatus, and the top electrode is Ag, Al, Au or ITO.

[0039] The present invention uses magnetron sputtering and solution method to prepare Cs3Bi2Br9 / ZnO composite film as the active layer of memristor. The experimental method is simple and helps to overcome the challenges faced by the single solution method for constructing the active layer of perovskite memristor. It effectively improves the repetition rate of perovskite memristor preparation and effectively guarantees the stability of perovskite and device reliability. This will provide theoretical guidance and scientific basis for the further development of memristor technology, thereby promoting the further development and application of the memristor field and providing effective ideas for future memristor-related research.

[0040] The present invention constructs an ITO / Cs3Bi2Br9 / ZnO / Ag memristor, which has a lower operating voltage. In addition, a trace amount of HBr is added to the Cs3Bi2Br9 perovskite solution, which promotes its solubility and improves the quality of the film. Importantly, because of the end-capping of the ZnO film, not only is the Cs3Bi2Br9 film effectively prevented from contacting water and oxygen, but the performance of the device is also improved, so that the device preparation repetition rate is higher.

[0041] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A method for preparing a high-stability heterojunction material memristor, characterized in that: The following steps are involved: S1: fabricate samples, using conductive materials as substrate and bottom electrode; S2: preparing Cs3Bi2Br9 solution by mixing CsBr and BiBr3 powders with DMSO and DMF; S3: Mix and stir the Cs3Bi2Br9 solution in S2, add HBr after 1 hour, and continue to stir and mix; S4: Plasma treatment was performed on the S1 sample, and then the sample was spin-coated with Cs3Bi2Br9 solution; S5: Capping the sputtered ZnO film on the sample spin-coated in S4; S6: Plating the top electrode on the sample after ZnO film capping.

2. The method for preparing a high-stability heterojunction material memristor according to claim 1, characterized in that: The conductive material is ITO, FTO, or Si; The steps to prepare the samples include cutting and ultrasonic cleaning; The ultrasonic cleaning step comprises sequentially ultrasonicating in acetone, anhydrous ethanol and deionized water for 20-30 minutes.

3. The method for preparing a high-stability heterojunction material memristor according to claim 1, characterized in that: The Cs3Bi2Br9 solution is stirred at a rotation speed of 500-700 rpm / min, a temperature of 60-70°C, a stirring time of 2-3h, a molar ratio of CsBr to BiBr3 powder of 3:2, and a molar ratio of DMSO to DMF of 1:(4-9).

4. The method for preparing a high-stability heterojunction material memristor according to claim 1, characterized in that: The concentration of HBr is 48%, and the volume ratio of HBr to Cs3Bi2Br9 solution is 1:

200.

5. The method for preparing a high-stability heterojunction material memristor according to claim 1, characterized in that: The plasma treatment is carried out in a plasma cleaning machine for 5-10 minutes, the rotation speed when spin coating the Cs3Bi2Br9 solution is 4000-5000rpm / min, and the time is 40-50s; the anti-solvent is toluene or chlorobenzene, and the dripping time is 15-20s after the start of spin coating, and then the spin-coated sample is annealed at a temperature of 100-120°C and a time of 10-15min.

6. The method for preparing a high-stability heterojunction material memristor according to claim 1, characterized in that: The ZnO film is sputtered by a magnetron sputtering apparatus, and the parameters are as follows: sputtering gas pressure 0.4-0.6 Pa, sputtering Ar gas flow rate 30-40 sccm, sputtering power 80-90 W, and sputtering time 12-15 min.

7. The method for preparing a high-stability heterojunction material memristor according to claim 1, characterized in that: The magnetron sputtering top electrode is Ag, Al, Au or ITO.

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