阅读说明：本技术 一种后处理制备梯度带隙钙钛矿薄膜的装置及方法 (Device and method for preparing gradient band gap perovskite film through post-treatment ) 是由 殷建 张超 魏俊峰 申绪男 冯洋 赖运子 熊元 杨明 杨立 于 2020-07-16 设计创作，主要内容包括：本发明属于薄膜制备领域,具体属于后处理制备梯度带隙钙钛矿薄膜的装置及方法。包括加热基板；加热基板上端设有气氛保护罩,气氛保护罩内的加热基板上端连接有两个高度相等且平行的垫块,垫块上方放置有涂覆有薄膜的基底；基底下方的加热基板上设有机卤化胺盐,有机卤化胺盐正对基底带有薄膜的一侧。所述方法包括如下步骤：首先将生长有有机卤化胺盐薄膜的基底放置在垫块上；在加热基板上放置一定量的有机卤化胺盐粉末；盖上气氛保护罩,调节加热台温度并保温,随后自然冷却至室温；得到梯度带隙CH<Sub>3</Sub>NH<Sub>3</Sub>Pb(Br,I)<Sub>3</Sub>钙钛矿薄膜。该发明可实现新型钙钛矿材料单晶及多晶薄膜的梯度带隙制备,实现薄膜中卤素的梯度分布进而形成梯度带隙。(The invention belongs to the field of film preparation, and particularly belongs to a device and a method for preparing a gradient band gap perovskite film through aftertreatment. Comprises heating a substrate; an atmosphere protection cover is arranged at the upper end of the heating substrate, two cushion blocks which are equal in height and parallel to each other are connected to the upper end of the heating substrate in the atmosphere protection cover, and a substrate coated with a thin film is placed above the cushion blocks; the heating substrate below the base is provided with organic amine halide salt, and the organic amine halide salt is opposite to the side of the base with the film. The method comprises the following steps: firstly, placing a substrate on which an organic amine halide salt film grows on a cushion block; placing a certain amount of organic amine halide salt powder on a heating substrate; covering an atmosphere protection cover, adjusting the temperature of the heating table and preserving heatThen naturally cooling to room temperature; obtaining a gradient band gap CH 3 NH 3 Pb(Br,I) 3 A perovskite thin film. The invention can realize the preparation of the gradient band gap of the novel perovskite material single crystal and polycrystalline film, and realize the gradient distribution of halogen in the film so as to form the gradient band gap.)

1. A device for preparing a gradient band gap perovskite thin film through aftertreatment is characterized in that: comprises a heating table, wherein a heating substrate is arranged on the heating table; the upper end of the heating substrate in the atmosphere protection cover is movably connected with two parallel cushion blocks with equal height, and a substrate coated with a thin film is placed above the cushion blocks; the heating substrate below the base is provided with organic amine halide salt, and the organic amine halide salt is opposite to the side of the base with the film.

2. The method of operating a post-treatment production gradient bandgap perovskite thin film device according to claim 1, comprising the steps of:

s1, firstly, preparing a single halogen bottom layer perovskite film, and placing a substrate with the film on a cushion block with a certain thickness to enable the distance between the film and the upper end of a heating substrate to be 1-50 mm;

s2, placing a certain amount of organic amine halide salt powder on the clean heating substrate, wherein the powder is opposite to the center of the film;

s3, covering an atmosphere protection cover, adjusting the temperature of the heating table to 80-200 ℃, keeping the temperature for 1-24 hours, and then naturally cooling to room temperature; obtaining the gradient band gap perovskite film.

3. The method of post-processing to produce a gradient bandgap perovskite thin film device of claim 2, wherein: every 1cm in S2²The film is used in an amount of 0.01 to 1g of an organic amine halide salt.

4. The method of post-treating a device for making a gradient bandgap perovskite thin film of claim 2, wherein the organic amine halide salt comprises but is not limited to one of methylamine hydroiodide, ethylamine hydroiodide, propylamine hydroiodide, butylamine hydroiodide, aniline hydroiodide and benzylamine hydroiodide.

Technical Field

The invention belongs to the field of film preparation, and particularly belongs to a device and a method for preparing a gradient band gap perovskite film through aftertreatment.

Background

In recent years, new perovskite materials have shown great application potential in the field of solar cells, and the progress of commercialization is being pursued. Based on the optimization of the structure and the material, although the organic-inorganic composite perovskite material single junction battery breaks through the photoelectric conversion efficiency of 25%, the organic-inorganic composite perovskite material single junction battery has a certain gap from silicon, and meanwhile, the stability and the atmospheric preparation of the organic-inorganic composite perovskite material single junction battery are still very challenging. The all-inorganic perovskite material battery has the advantages of higher stability and direct preparation in the air, is more convenient for industrialized preparation, but has lower efficiency. At present, the efficiency improvement of the unijunction perovskite solar cell through the structure and material optimization of the unijunction perovskite solar cell reaches a bottleneck stage, the efficiency can be further improved only by adopting a lamination method, but the preparation process of the lamination solar cell is complex, the preparation of more layer materials is required, the thickness and matching problem of each layer is also considered, and the unijunction perovskite solar cell is not beneficial to industrialized preparation.

The gradient band gap light absorption layer is another way to improve the efficiency of the solar cell, which is attached to the original growth process, does not need complicated structure design and matching, and is arranged at CIGS and the like are better applied to mature solar cells. The existing method for preparing the gradient band gap perovskite material solar cell mainly comprises continuous solution spin coating and continuous physical vapor deposition processes for adding a protective layer. In 2016, Alex Zettl team at Berkeley university, California, who prepared organic-inorganic composite perovskite gradient band gap solar cells on GaN by using solution continuous spin coating to prepare CH₃NH₃SnI₃And CH₃NH₃PbI_3-xBr_xThe middle was separated with a monolayer of h-BN to prevent ion mixing, after which a hole transport layer and a current collection layer (Au) were spin coated. In 2019, the combined fertilizer industry university Material science and engineering college Jiang Yang professor topic group is combined with the Japanese Chongrope science and technology college Yabin Qi professor topic group, and the preparation of the all-inorganic CsPbBr by adopting the continuous physical vapor deposition process is proposed₃And its derived phase CsPb₂Br₅，Cs₄PbBr₆The gradient band gap perovskite thin film.

The gradient band gap films are all gradient films made of materials with different structures, are not beneficial to component transition and charge transmission between layers, and need modification of a transition layer, so that the preparation process is difficult. The continuous vacuum evaporation process requires expensive equipment, high energy consumption and low preparation efficiency, and is not beneficial to the large-scale production of the perovskite solar cell.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a device and a method for preparing a homogeneous (same-structure) gradient perovskite thin film through post-treatment. The invention may realize novel perovskite materials (including but not limited to ABX₃，A₂BX₄Structures wherein A includes but is not limited to Cs⁺，MA⁺，FA⁺B includes but is not limited to Pb, Sn; x is a halogen atom. ) The gradient band gap preparation of monocrystal and polycrystal film is characterized by that it utilizes gas phase to introduce R-NH₃-X₁By the use of X₁Substituting the original halogen ion X in the film₂And the gradient distribution of halogen in the film is realized, so that a gradient band gap is formed.

The technical scheme adopted by the invention for solving the technical problems in the prior art is as follows:

the invention discloses a device for preparing a gradient band gap perovskite film through aftertreatment, which comprises a heating table, wherein a heating substrate is arranged on the heating table; the upper end of the heating substrate in the atmosphere protection cover is movably connected with two parallel cushion blocks with equal height, and a substrate coated with a thin film is placed above the cushion blocks; the heating substrate below the base is provided with organic amine halide salt, and the organic amine halide salt is opposite to the side of the base with the film.

In a further technical scheme, the invention discloses a method for preparing a gradient band gap perovskite thin film by post-treatment, which comprises the following steps:

s1, preparing a single halogen bottom layer perovskite film by adopting a common coating mode such as a spin coating method, a blade coating method and the like, and placing a substrate with the film on a cushion block with a certain thickness to enable the distance between the film and the upper end of a heating substrate to be 1-50 mm;

s2, placing a certain amount of organic amine halide salt powder on the clean heating substrate, wherein the powder is opposite to the center of the film;

s3, covering an atmosphere protection cover, adjusting the temperature of the heating table to 80-200 ℃, keeping the temperature for 1-24 hours, and then naturally cooling to room temperature; obtaining the gradient band gap perovskite film.

In a further technical scheme, each 1cm²The film is used in an amount of 0.01 to 1g of an organic amine halide salt.

In a further embodiment, the organic amine halide salt includes, but is not limited to, methylamine hydroiodide (CH)₃NH₃I) Ethylamine hydroiodide (C)₂H₅NH₃I) Propylamine hydroiodide (i-C)₃H₇NH₃I) Butylamine hydroiodide (i-C)₄H₉NH₃I) Aniline hydroiodide (C)₆H₅NH₃I) And phenylmethylamine hydroiodide (C)₇H₇NH₃I) One kind of (1).

Has the advantages and positive effects that:

the traditional continuous vacuum evaporation process needs expensive equipment, higher energy consumption and low preparation efficiency, and is not beneficial to the large-scale production of the perovskite solar cell. The device is simple and cheap, consumes less energy, can be used for heating a flat plate and can also be heated by using a vacuum oven, and is cheap and easy to obtain, and easy to amplify and produce.

Compared with the existing preparation scheme of the gradient film, the technical scheme of the invention has the following obvious advantages:

the method realizes the preparation of the gradient band gap of the perovskite thin film with the same crystal structure, partial ion substitution is carried out by means of the original crystal structure, the crystal structure is not obviously changed, the ion diffusion is uniform, the band gap transition is uniform, the defects are few, the influence on charge transmission and recombination in the using process of the thin film is small, and the method has important significance on maintaining the photoelectric property of the thin film.

The gradient band gap of the non-homostructural material is made into a transition layer to avoid lattice mismatch at the joint, so that the process steps and difficulty are increased, and the gradient band gap of the homostructural material realized by the method can be avoided.

Drawings

FIG. 1 is a schematic view of the apparatus of the present invention;

FIG. 2 is a schematic diagram of the gradual substitution of halogen ions in the thin film structure by halogen ions in the organoamine halide salt of the present invention;

FIG. 3 shows CH before and after treatment in the present invention₃NH₃PbBr₃A surface color contrast map;

FIG. 4 shows XRD test patterns and CH before and after thin film treatment in accordance with the present invention₃NH₃PbBr₃And (5) comparing powder standard maps.

Wherein:

1. heating the substrate; 2. an atmosphere protection cover; 3. cushion blocks; 4. a substrate; 5. an organoamine halide salt.

Detailed Description

In order to further understand the contents, features and effects of the present invention, the following embodiments are illustrated and described in detail with reference to the accompanying drawings:

as shown in figure 1, the invention discloses a device for preparing a gradient band gap perovskite thin film by post-treatment, which comprises a heating table, wherein a heating substrate 1 is arranged on the heating table; a hollow atmosphere protection cover 2 with an opening at one end is arranged at the upper end of the heating substrate 1, two parallel cushion blocks 3 with equal height are movably connected at the upper end of the heating substrate 1 in the atmosphere protection cover 2, and a substrate 4 coated with a thin film is placed above the cushion blocks 3; the organic amine halide salt 5 is arranged on the heating substrate 1 below the base 4, and the organic amine halide salt 5 is opposite to the side of the base 4 with the film. According to the invention, the organic ammonium halide salt 5 is volatilized by reaching a melting point in the heating process of the heating substrate 1, the atmosphere of the organic ammonium halide salt 5 is generated in the atmosphere protection cover 2, halogen ions gradually enter the film and replace the original halogen ions in the film structure, the entering depth of the halogen ions can be controlled according to the heating time, so that a band gap gradient is generated, the organic part which does not enter is attached to the surface of the film, the water and oxygen stability of the film is enhanced, and the principle schematic diagram of ion replacement is shown in FIG. 2;

preferably, the heating table and the atmosphere protection cover 2 can be replaced by a vacuum drying oven.

The invention also discloses a method for preparing the gradient band gap perovskite film by post-treatment, which comprises the following steps:

s1, placing the substrate 4 with the organic amine halide salt 5 film on a cushion block 3 with the thickness of 1mm, and enabling the distance between the film and the upper end of the heating substrate 1 to be 1-50 mm;

s2, placing a certain amount of CH on the cleaned heating substrate 1₃NH₃I, powder, wherein the powder is opposite to the center of the film;

s3, covering the atmosphere protection cover 2, adjusting the temperature of the heating table to 80-200 ℃, keeping the temperature for 1-24 hours, and then naturally cooling to room temperature; obtaining a gradient band gap CH₃NH₃Pb(Br,I)₃A perovskite thin film.

Preferably, the amount of the organic amine halide salt 5 is selected according to the area of the film, specifically, per 1cm²The film is used for 0.01 to 1g of organic amine halide salt 5.

Preferably, the organic amine halide salt 5 includes, but is not limited to, methylamine hydroiodide (CH)₃NH₃I) Ethylamine hydroiodide (C)₂H₅NH₃I) Propylamine hydroiodide (i-C)₃H₇NH₃I) Butylamine hydroiodide (i-C)₄H₉NH₃I) Aniline hydroiodide (C)₆H₅NH₃I) And phenylmethylamine hydroiodide (C)₇H₇NH₃I) One kind of (1).

The invention can adjust the distance between the film and the organic ammonium halide salt 5 by replacing the cushion blocks 3 with different thicknesses so as to control the volatilization distance.