A perovskite multilayer SnO 2 Buffer film, battery and preparation method thereof

Abstract

The present invention discloses a perovskite multilayer SnO2 buffer film, a battery and a preparation method thereof, wherein the perovskite multilayer SnO2 buffer film comprises a pretreatment film layer, a first SnO2 film layer and a second SnO2 film layer in sequence, wherein the thickness of the first SnO2 film layer is less than the thickness of the second SnO2 film layer. The perovskite multilayer SnO2 buffer film provided by the present invention comprises at least three film layers, and the deposition rate and thickness of each film layer can be controlled. The multilayer SnO2 buffer film prepared by the linear reciprocating atomic layer deposition equipment of the present invention not only improves the uniformity of the film layer while ensuring the uniformity of the film layer of a large-size substrate, but also improves the deposition rate to a certain extent, saves process time, and optimizes the production cycle.

Description

Technical Field

[0001] The present invention relates to a buffer film, a battery and a preparation method thereof, and in particular to a perovskite multilayer SnO2 buffer film, a battery and a preparation method thereof. Background Art

[0002] As an important component of perovskite cell devices, SnO2 buffer layer can effectively transport electrons. As a promising electron transport material, SnO2 has the advantages of high mobility, wide band gap, deep conduction band and valence band, and has been well studied in many perovskite solar cells. It is a common technique to prepare SnO2 using atomic layer deposition (ALD).

[0003] Spatially isolated atomic layer deposition (SALD) technology is a thin film growth technology developed based on ALD technology, including rotary SALD, roll-to-roll SALD and linear reciprocating SALD. Compared with traditional time-isolated atomic layer deposition technology, spatially isolated atomic layer deposition technology has the characteristics of large area, large scale, continuous production and can even be applied to flexible substrates. However, when using linear reciprocating SALD to prepare SnO2 thin film, the substrate movement speed affects the distribution range of precursor concentration. Too fast speed causes air flow disturbance, and then the chemical vapor deposition (CVD) reaction increases, affecting the film quality, while too slow speed affects the deposition rate, resulting in an increase in film formation time and affecting the production cycle. Therefore, it is necessary to develop a process that can optimize both film quality and film formation rate. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a perovskite multilayer SnO2 buffer film, a battery and a preparation method thereof, which is suitable for a linear reciprocating space-type atomic layer deposition device, and solves the problem of excessive CVD reaction resulting in poor film quality and slow deposition rate when the space-type atomic layer deposition device prepares SnO2 thin films.

[0005] The technical solution adopted by the present invention to solve the above technical problems is to provide a perovskite multilayer SnO2 buffer film, which includes a pretreatment film layer, a first SnO2 film layer and a second SnO2 film layer in sequence, and the thickness of the first SnO2 film layer is less than the thickness of the second SnO2 film layer.

[0006] Furthermore, the thickness of the first SnO2 film is 4-6 nm, and the thickness of the second SnO2 film is 14-16 nm.

[0007] In order to solve the above technical problems, the present invention also provides a trans-structured perovskite battery, comprising FTO glass, wherein a nickel oxide hole transport layer, a perovskite layer, a C 60 An electron transport layer, a pretreatment film layer and a multi-layer SnO2 buffer film, wherein the multi-layer SnO2 buffer film is the above-mentioned perovskite multi-layer SnO2 buffer film.

[0008] Furthermore, the specification of the FTO glass is 2.5×2.5 cm; the thickness of the nickel oxide hole transport layer is 20 nm, and it is prepared on the surface of the FTO glass by magnetron sputtering; the thickness of the perovskite layer is 600 nm, and it is prepared on the surface of the nickel oxide hole transport layer by blade coating; 60 The thickness of the electron transport layer is 10 nm and is prepared on the surface of the perovskite layer by evaporation.

[0009] In order to solve the above technical problems, the present invention also provides a method for preparing the above-mentioned perovskite multilayer SnO2 buffer film, which includes the following steps: S1: placing a substrate in a vacuum constant temperature chamber; S2: constructing a pretreatment film, introducing a TDMASn precursor and an isolation gas N2 into the chamber, a roller driving the substrate to swing, setting a first swinging speed, and exposing the swinging substrate to the TDMASn precursor reaction area and the isolation gas N2 area in turn. After the substrate completes adsorption in the TDMASn reaction area, it swings to the isolation area to wash away excess precursors and reaction by-products, and after reciprocating motion, a pretreatment film layer is obtained; S3: constructing the first layer of film: introducing a TDMASn precursor, an isolation gas N2 and an H2O precursor to the surface of the pretreated substrate, setting a second swinging speed, and exposing the swinging substrate to the TDMASn precursor reaction area, the isolation gas N2 reaction area and the H2O precursor area in turn. After the substrate completes adsorption in the TDMASn reaction area , swing to the isolation area to clean off excess precursors and reaction by-products, and then swing to the H2O reaction area for reaction, to achieve a complete atomic layer deposition reaction process, and after reciprocating motion, a first layer of SnO2 film is obtained; S4: construct the second layer of film: introduce TDMASn precursor, isolation gas N2 and H2O precursor to the substrate with the first layer of SnO2 film, set a third swing speed, and swing the substrate to expose it to the TDMASn precursor reaction area, the isolation gas N2 reaction area and the H2O precursor area in turn. After the substrate completes adsorption in the TDMASn reaction area, it swings to the isolation area to clean off excess precursors and reaction by-products, and then swings to the H2O reaction area for reaction, to achieve a complete atomic layer deposition reaction process, and after reciprocating motion, a second layer of SnO2 film is obtained; S5: introduce isolation N2 into the chamber, then evacuate, repeat this process, clean up the remaining reaction gas and by-products in the chamber, and obtain a multilayer SnO2 buffer film.

[0010] Furthermore, the third swing speed is greater than the first swing speed and the second swing speed, so that the thickness of the first film layer in step S3 is less than the thickness of the second film layer in step S4.

[0011] Furthermore, in the step S2, the first swing speed is 4000-6000 mm / min, 400-600 sccm of TDMASn and 7000-8000 sccm of N2 are introduced and mixed before entering the chamber as the first process gas; 20000-30000 sccm of isolation gas N2 is introduced as the second process gas, and the carrier with the substrate is swung for 3-10 times to pre-treat the substrate.

[0012] Furthermore, in the step S3, the second swing speed is 4000-6000m / min, 400-600sccm of TDMASn and 7000-8000sccm of N2 are introduced and mixed before entering the cavity as the first process gas; 20000-30000sccm of isolation gas N2 is introduced as the second process gas, 100-200sccm of water vapor and 11000-12000sccm of N2 are introduced and mixed before entering the cavity as the third process gas, and the carrier with the substrate is swung for 15-20 times to obtain the first layer of SnO2 film.

[0013] Furthermore, in the step S4, the third swing speed is 8000-10000 mm / min, 400-600 sccm of TDMASn and 7000-8000 sccm of N2 are introduced and mixed before entering the cavity as the first process gas; 20000-30000 sccm of isolation gas N2 are introduced as the second process gas; 100-200 sccm of water vapor and 11000-12000 sccm of N2 are introduced and mixed before entering the cavity as the third process gas, and the carrier with the substrate is swung for 60-70 times to obtain a second layer of SnO2 film.

[0014] Furthermore, in the step S5, 10000-15000 sccm of isolation gas N2 is introduced for 10-20 seconds, followed by vacuuming for 30-50 seconds, which is repeated 5-10 times.

[0015] Compared with the prior art, the present invention has the following beneficial effects: the perovskite multilayer SnO2 buffer film provided by the present invention includes at least three film layers, and the deposition rate and thickness of each film layer can be controlled. The multilayer SnO2 buffer film prepared by the present invention using a linear reciprocating atomic layer deposition device not only improves the uniformity of the film layer while ensuring the uniformity of the film layer of a large-size substrate, but also improves the deposition rate to a certain extent, saves process time, and optimizes the production cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The schematic diagram of the structure of the perovskite battery containing a multi-layer SnO2 buffer film of the present invention;

[0017] Figure 2 Schematic diagram of the preparation process of the multilayer SnO2 buffer film of the present invention;

[0018] Figure 3 This is a schematic diagram of the structure of the spatial ALD process chamber used in the present invention;

[0019] Figure 4 It is a schematic diagram of the test point distribution of the uniformity of the multi-layer SnO2 buffer film of the present invention. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0021] The perovskite multilayer SnO2 buffer film provided by the present invention comprises a pretreatment film layer, a first SnO2 film layer and a second SnO2 film layer in sequence, wherein the thickness of the first SnO2 film layer is less than the thickness of the second SnO2 film layer. Preferably, the thickness of the pretreatment film layer is less than 1nm, and only one Sn atomic layer is covered, and no SnO2 film layer is generated; the thickness of the first SnO2 film layer ranges from 4-6nm, and a thickness below 4nm affects the film quality, and a thickness above 6nm increases the coating time, and a preferred value is 5nm; the thickness of the second SnO2 film layer ranges from 14-16nm, and a thickness below 14nm increases the coating time, and a thickness above 16nm affects the film quality, and a preferred value is 15nm.

[0022] The inverse structure perovskite battery provided by the present invention comprises FTO glass, on which a nickel oxide hole transport layer, a perovskite layer, a C 60 The electron transport layer, the pretreatment film layer and the above-mentioned multilayer SnO2 buffer film, such as Figure 1 shown.

[0023] Please continue to see Figure 2 The method for preparing the perovskite multilayer SnO2 buffer film of the present invention comprises the following steps:

[0024] S1: placing the substrate in a vacuum thermostatic chamber;

[0025] S2: construct a pretreatment film, introduce tetrakis(dimethylamino)tin (TDMASn) precursor and isolation gas N2 into the chamber, drive the substrate to swing with a roller, set a first swing speed, and expose the swinging substrate to the TDMASn precursor reaction area and the isolation gas N2 area in turn. After the substrate completes adsorption in the TDMASn reaction area, it swings to the isolation area to clean off excess precursors and reaction by-products. After reciprocating motion, a pretreatment film layer is obtained;

[0026] S3: constructing the first film: introducing TDMASn precursor, isolation gas N2 and H2O precursor to the pretreated substrate surface, setting a second swing speed, and swinging the substrate to expose it to the TDMASn precursor reaction area, the isolation gas N2 reaction area and the H2O precursor area in turn. After the substrate completes adsorption in the TDMASn reaction area, it swings to the isolation area to clean off excess precursors and reaction by-products, and then swings to the H2O reaction area for reaction, realizing a complete atomic layer deposition reaction process. After reciprocating motion, the first SnO2 film is obtained;

[0027] S4: constructing the second film: introducing TDMASn precursor, isolation gas N2 and H2O precursor to the substrate with the first SnO2 film, setting a third swing speed, and exposing the swing substrate to the TDMASn precursor reaction area, the isolation gas N2 reaction area and the H2O precursor area in turn. After the substrate completes adsorption in the TDMASn reaction area, it swings to the isolation area to clean off excess precursors and reaction by-products, and then swings to the H2O reaction area for reaction, realizing a complete atomic layer deposition reaction process. After reciprocating motion, a second SnO2 film is obtained;

[0028] S5: Introduce isolated N2 into the chamber, then evacuate the chamber, repeat this process, clean the remaining reaction gas and by-products in the chamber, and obtain a multilayer SnO2 buffer film.

[0029] The third swing speed in S4 is greater than the first and second swing speeds in S2 and S3, and the first film thickness in S3 is less than the second film thickness in S4. Preferably, the swing speed is between 4000-10000 mm / min. If the swing speed is lower than 4000 mm / min, the deposition rate will be slow and the coating time will be too long; if the swing speed is higher than 10000 mm / min, the CVD reaction will increase and the film quality will deteriorate.

[0030] Figure 3 Schematic diagram of the structure of the spatial ALD process chamber used in the present invention, wherein the chamber cover ① is used to connect the jet panel and the chamber switch cover; the jet panel ② is used to ensure uniform gas spraying during the process; and the first carrier plate ③ is used to place experimental samples.

[0031] The present invention also provides a method for preparing an inverse structure perovskite battery, comprising the following steps:

[0032] (1) Cleaning FTO glass with a size of 2.5×2.5 cm;

[0033] (2) A 20 nm nickel oxide hole transport layer was prepared on the FTO glass surface by magnetron sputtering;

[0034] (3) Preparing a 600 nm perovskite layer on the surface of the nickel oxide hole transport layer by a doctor blade coating method;

[0035] (4) Prepare 10 nm C on the surface of the perovskite layer by evaporation 60 Electron transport layer;

[0036] (5) In C 60 A multilayer SnO2 buffer film is prepared on the surface of the electron transport layer by the method described above;

[0037] (6) Preparing a metal copper electrode on the surface of the multilayer SnO2 buffer film layer to obtain the inverse perovskite battery structure as shown in Figure 4 shown.

[0038] Example 1

[0039] This embodiment provides a method for preparing a multilayer SnO2 buffer film. The process flow chart of the preparation method is as follows: Figure 1 As shown, the preparation method adopts Figure 2 The spatial ALD device shown in the figure, the preparation method comprises the following steps:

[0040] In S1, the substrate is placed in a vacuum constant temperature chamber, the vacuum degree of the chamber is 10Pa, and the chamber temperature is 220°C;

[0041] In S2, the first swing speed is 4000-6000 mm / min, 400-600 sccm of TDMASn and 7000-8000 sccm of N2 are introduced and mixed before entering the chamber as the first process gas, 20000-30000 sccm of isolation gas N2 is introduced as the second process gas, and the carrier with the substrate is swung for 3-10 times to pre-treat the substrate;

[0042] In S3, the second swing speed is 4000-6000 m / min, 400-600 sccm of TDMASn and 7000-8000 sccm of N2 are introduced and mixed before entering the cavity as the first process gas, 20000-30000 sccm of isolation gas N2 is introduced as the second process gas, 100-200 sccm of water vapor and 11000-12000 sccm of N2 are introduced and mixed before entering the cavity as the third process gas, and the carrier with the substrate is swung for 15-20 times to obtain the first SnO2 film;

[0043] In S4, the third swing speed is 8000-10000 mm / min, 400-600 sccm of TDMASn and 7000-8000 sccm of N2 are introduced and mixed before entering the chamber as the first process gas, 20000-30000 sccm of isolation gas N2 is introduced as the second process gas, 100-200 sccm of water vapor and 11000-12000 sccm of N2 are introduced and mixed before entering the chamber as the third process gas, and the carrier with the substrate is swung for 60-70 times to obtain a second SnO2 film;

[0044] In S5, 10000-15000 sccm of isolation gas N2 is introduced for 10-20 seconds, followed by vacuuming for 30-50 seconds. This is repeated 5-10 times to complete the process and obtain the multilayer SnO2 buffer film.

[0045] Comparative Example 1

[0046] This comparative example provides a method for preparing a single-layer SnO2 buffer film, the preparation method adopts the film preparation equipment as described in Example 1, and the preparation method comprises the following steps:

[0047] In S1, the substrate is placed in a vacuum constant temperature chamber, the vacuum degree of the chamber is 10Pa, and the chamber temperature is 220°C;

[0048] In S2, the swing speed is 4000-6000 mm / min, 400-600 sccm of TDMASn and 7000-8000 sccm of N2 are introduced and mixed before entering the chamber as the first process gas, 20000-30000 sccm of isolation gas N2 is introduced as the second process gas, and the carrier with the substrate is swung for 3-10 times to pre-treat the substrate;

[0049] In S3, the swing speed is 4000-6000 m / min, 400-600 sccm of TDMASn and 7000-8000 sccm of N2 are introduced and mixed before entering the chamber as the first process gas, 20000-30000 sccm of isolation gas N2 is introduced as the second process gas, 100-200 sccm of water vapor and 11000-12000 sccm of N2 are introduced and mixed before entering the chamber as the third process gas, and the carrier with the substrate is swung for 70-80 times to obtain a single layer of SnO2 film;

[0050] S4 is not performed;

[0051] In S5, 10000-15000 sccm of isolation gas N2 is introduced for 10-20 seconds, followed by vacuuming for 30-50 seconds. This is repeated 5-10 times to complete the process and obtain the multilayer SnO2 buffer film.

[0052] The multilayer SnO2 buffer film prepared in Example 1 and Comparative Example 1 was tested for film thickness uniformity using an ellipsometer. The test positions were 9 10×10 cm glasses evenly distributed on a 1×2 m carrier. The test points were as follows: Figure 4 As shown; the second carrier ④ is used to place the test sample; ⑤ is the point for placing the multi-layer SnO2 buffer film sample, which can be glass or a semi-finished battery with a perovskite layer prepared, used to test the uniformity of the film layer. The uniformity calculation formula is as follows: (Max-Min) / (Max+Min)×100%

[0053] The film thickness (in nm) and uniformity test results at each point are shown in Table 1 below:

[0054]

[0055] It can be seen from the above table that a SnO2 film layer with good uniformity can be prepared through the single-layer SnO2 layer preparation process (Comparative Example 1). However, after adopting the preparation method of the multi-layer SnO2 buffer film of the present invention, while ensuring excellent uniformity, the multi-layer SnO2 buffer film improves the deposition rate, and the total coating time is reduced from 294 seconds to 266 seconds, which saves process time and is conducive to the optimization of production rhythm.

[0056] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make some modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the definition of the claims.

Claims

1. A method for preparing a perovskite multilayer SnO2 buffer film, characterized in that: The perovskite multilayer SnO2 buffer film includes a pretreatment film layer, a first SnO2 film layer and a second SnO2 film layer in sequence, and the thickness of the first SnO2 film layer is less than the thickness of the second SnO2 film layer; The preparation method comprises the following steps: S1: placing the substrate in a vacuum constant temperature chamber; S2: construct a pretreatment film, introduce TDMASn precursor and isolation gas N2 into the chamber, drive the substrate to swing with a roller, set a first swing speed, and expose the swinging substrate to the TDMASn precursor reaction area and the isolation gas N2 area in turn. After the substrate completes adsorption in the TDMASn reaction area, it swings to the isolation area to clean off excess precursors and reaction by-products. After reciprocating motion, a pretreatment film layer is obtained; S3: constructing the first film: introducing TDMASn precursor, isolation gas N2 and H2O precursor to the pretreated substrate surface, setting a second swing speed, and swinging the substrate to expose it to the TDMASn precursor reaction area, the isolation gas N2 reaction area and the H2O precursor area in turn. After the substrate completes adsorption in the TDMASn reaction area, it swings to the isolation area to clean off excess precursors and reaction by-products, and then swings to the H2O reaction area for reaction, realizing a complete atomic layer deposition reaction process. After reciprocating motion, the first SnO2 film is obtained; S4: constructing the second film: introducing TDMASn precursor, isolation gas N2 and H2O precursor to the substrate with the first SnO2 film, setting a third swing speed, and exposing the swing substrate to the TDMASn precursor reaction area, the isolation gas N2 reaction area and the H2O precursor area in turn. After the substrate completes adsorption in the TDMASn reaction area, it swings to the isolation area to clean off excess precursors and reaction by-products, and then swings to the H2O reaction area for reaction, realizing a complete atomic layer deposition reaction process. After reciprocating motion, a second SnO2 film is obtained; S5: introducing isolated N2 into the chamber, then evacuating the chamber, repeating this process to clean the remaining reaction gas and by-products in the chamber, and obtaining a multilayer SnO2 buffer film; The third swing speed is greater than the first swing speed and the second swing speed, and the number of swings in step S4 is greater than the number of swings in step S3 and step S2; so that the thickness of the pre-treated film layer is less than 1nm, covering only one Sn atomic layer; so that the thickness of the first film layer in step S3 is less than the thickness of the second film layer in step S4.

2. The method for preparing a perovskite multilayer SnO2 buffer film according to claim 1, characterized in that: The thickness of the first SnO2 film is 4-6 nm, and the thickness of the second SnO2 film is 14-16 nm.

3. The method for preparing a perovskite multilayer SnO2 buffer film according to claim 1, characterized in that: In the step S2, the first swing speed is 4000-6000 mm / min, 400-600 sccm of TDMASn and 7000-8000 sccm of N2 are introduced and mixed before entering the chamber as the first process gas; 20000-30000 sccm of isolation gas N2 is introduced as the second process gas, and the carrier with the substrate is swung for 3-10 times to pre-treat the substrate.

4. The method for preparing a perovskite multilayer SnO2 buffer film according to claim 1, characterized in that: In the step S3, the second swing speed is 4000-6000m / min, 400-600sccm of TDMASn and 7000-8000sccm of N2 are introduced and mixed before entering the cavity as the first process gas; 20000-30000sccm of isolation gas N2 is introduced as the second process gas, 100-200sccm of water vapor and 11000-12000sccm of N2 are introduced and mixed before entering the cavity as the third process gas, and the carrier with the substrate is swung for 15-20 times to obtain the first layer of SnO2 film.

5. The method for preparing a perovskite multilayer SnO2 buffer film according to claim 1, characterized in that: In the step S4, the third swing speed is 8000-10000 mm / min, 400-600 sccm of TDMASn and 7000-8000 sccm of N2 are introduced and mixed before entering the cavity as the first process gas; 20000-30000 sccm of isolation gas N2 is introduced as the second process gas; 100-200 sccm of water vapor and 11000-12000 sccm of N2 are introduced and mixed before entering the cavity as the third process gas, and the carrier with the substrate is swung for 60-70 times to obtain a second layer of SnO2 film.

6. The method for preparing a perovskite multilayer SnO2 buffer film according to claim 1, characterized in that: In the step S5, 10000-15000 sccm of isolation gas N2 is introduced for 10-20 seconds, followed by vacuuming for 30-50 seconds, which is repeated 5-10 times.

7. An inverse structure perovskite battery, comprising FTO glass, characterized in that: The FTO glass is provided with a nickel oxide hole transport layer, a perovskite layer, a C 60 An electron transport layer and a multilayer SnO2 buffer film, wherein the multilayer SnO2 buffer film is prepared by the method of claim 1.

8. The inverted perovskite cell according to claim 7, characterized in that: The specification of the FTO glass is 2.5×2.5 cm; the thickness of the nickel oxide hole transport layer is 20 nm, and it is prepared on the surface of the FTO glass by magnetron sputtering; the thickness of the perovskite layer is 600 nm, and it is prepared on the surface of the nickel oxide hole transport layer by scraping; the C 60 The thickness of the electron transport layer is 10 nm and is prepared on the surface of the perovskite layer by evaporation.

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