An annealing device, an annealing method, and a preparation method for a perovskite layer

Abstract

The present invention discloses an annealing device, an annealing method and a perovskite layer preparation method. Among them, the annealing device is used to heat and crystallize the perovskite layer. The annealing device includes a radiation light source and a carrier table; the radiation light source is used to generate radiation light, and the radiation light is used to heat the perovskite layer; the carrier table is disposed opposite to the radiation light source and is used to support a substrate attached with the perovskite layer; a rough layer is disposed on a side of the carrier table facing the radiation light source, the rough layer is located on a side of the perovskite layer facing away from the radiation light source, and the rough layer receives the radiation light penetrating the perovskite layer and scatters at least part of the radiation light to the perovskite layer. The annealing device, annealing method and perovskite layer preparation method of the present invention are used to improve the crystallization quality of the perovskite layer after annealing.

Description

Technical Field

[0001] The present invention relates to the technical field of annealing devices, and in particular to an annealing device, an annealing method, and a perovskite layer preparation method. Background Art

[0002] The perovskite layer is the core structural layer that determines the photoelectric conversion efficiency of perovskite solar cells. When preparing the perovskite layer, generally, a perovskite precursor solution is coated on a glass substrate to form a liquid perovskite layer, and then steps such as solvent removal drying and annealing crystallization are performed on the liquid perovskite layer to obtain the required perovskite layer.

[0003] The existing method for annealing the perovskite layer is generally thermal conduction annealing. In the thermal conduction annealing method, generally, the glass substrate coated with the perovskite layer is placed on a hot plate, and then the hot plate generates heat and conducts it to the perovskite layer through the glass substrate to perform annealing treatment on the perovskite layer. This method requires the hot plate to be heated to a relatively high temperature, and the glass substrate may be bent and deformed under the heating of the hot plate, resulting in uneven contact between the glass substrate and the hot plate, and further resulting in uneven heat distribution conducted from the hot plate to the perovskite layer, affecting the annealing crystallization quality of the perovskite layer. Summary of the Invention

[0004] The purpose of the present invention is to provide an annealing device, an annealing method, and a perovskite layer preparation method for improving the crystallization quality of the perovskite layer after annealing.

[0005] The purpose of the present invention is achieved by the following technical solutions:

[0006] An annealing device for heating and crystallizing a perovskite layer, comprising:

[0007] A radiation light source for generating radiation light, and the radiation light is used to heat the perovskite layer;

[0008] A carrier table disposed opposite to the radiation light source and used to support a substrate attached with a perovskite layer;

[0009] A rough layer is disposed on a side of the carrier table facing the radiation light source, the rough layer is located on a side of the perovskite layer facing away from the radiation light source, and the rough layer receives the radiation light penetrating the perovskite layer and scatters at least part of the radiation light to the perovskite layer.

[0010] Preferably, the rough layer is used to contact the substrate, and the carrier table supports the substrate in a contact manner. The root mean square of the height fluctuation of the rough layer is greater than 0.4 and less than 0.9, and the surface correlation length of the rough layer is 0.8 to 1.2 times the wavelength of the radiation light; the wavelength of the radiation light is 200 nm to 2 μm.

[0011] Preferably, the thickness of the substrate is 2 mm to 3.5 mm, the size of the substrate is 300 mm × 300 mm to 400 mm × 500 mm, and the substrate is a glass substrate.

[0012] Preferably, the rough layer and the substrate are arranged at intervals, and the carrier supports the substrate in a non-contact manner. The distance between the rough layer and the substrate is 1 μm to 100 μm; the root mean square of the height fluctuation of the rough layer is greater than 0.6 and less than 0.8, and the surface correlation length of the rough layer is 0.8 to 1.2 times the wavelength of the radiation light; the wavelength of the radiation light is 380 nm to 10 μm.

[0013] Preferably, the thickness of the substrate is 2 mm to 3.5 mm, the size of the substrate is 0.6 m × 1 m to 1.2 m × 2.4 m, and the substrate is a glass substrate.

[0014] Preferably, the substrate is FTO glass or ordinary glass; the perovskite layer is one or more of MAPbI3 perovskite thin film, FAPbI3 perovskite thin film, and CsFAPbI3 perovskite thin film.

[0015] Preferably, the rough layer and the carrier are of an integral structure, or the rough layer is a thin film attached to the surface of the carrier, and the material of the thin film is a metal material.

[0016] Preferably, the rough layer is formed on the carrier by etching, sputtering, or evaporation.

[0017] An annealing method, which is applied to the annealing device of any of the above, and the annealing method includes:

[0018] The radiation light source generates radiation light that irradiates the perovskite layer. Part of the radiation light is absorbed by the perovskite layer, and part of the radiation light penetrates the perovskite layer and the substrate and irradiates the rough layer;

[0019] The radiation light irradiating the rough layer is scattered and reflected on the rough layer, and at least part of the scattered radiation light propagates to the perovskite layer and oscillates repeatedly to increase the optical path of the radiation light in the perovskite layer.

[0020] Preferably, a transparent intermediate phase thin film is pre-formed on the perovskite layer. When the radiation light generated by the radiation light source passes through the perovskite layer, the transparent intermediate phase thin film absorbs part of the radiation light;

[0021] Wherein, the radiation light is directed at the target material.

[0022] Preferably, the substrate abuts against the rough layer, and the radiation light scattered at the rough layer passes through the substrate to enter the perovskite layer. The power of the radiation light source is 450 - 550 W, and the scanning speed is 1 - 3 mm / s;

[0023] Or, the substrate is spaced from the rough layer to form a spaced space, and the radiation light scattered at the rough layer passes through the spaced space and the substrate to enter the perovskite layer. The power of the radiation light source is 0.9 - 1.1 kW, and the scanning speed is 5 - 7 mm / s.

[0024] Preferably, it further includes that the perovskite layer absorbs the energy of the radiation light and gradually changes from a transparent state to a non - transparent state; before the perovskite layer changes to a non - transparent state, the radiation light generated by the radiation light source passes through the perovskite layer and is scattered by the rough layer to the perovskite layer and oscillates repeatedly; when the perovskite layer changes to a non - transparent state, the radiation light generated by the radiation light source is directly absorbed by the perovskite layer, and the radiation light passing through the perovskite layer is reflected or scattered by the rough layer to the perovskite layer and absorbed by the perovskite layer.

[0025] A method for preparing a perovskite layer includes:

[0026] Coating a perovskite precursor solution on a substrate to form a perovskite layer;

[0027] Performing preliminary desolvation on the perovskite layer to make the perovskite layer form a transparent intermediate - phase thin film;

[0028] Annealing the perovskite layer on the substrate by using any one of the above annealing methods.

[0029] Compared with the prior art, the beneficial effects of the present invention at least include:

[0030] By using radiation light as the energy source for annealing treatment, there is no need to set up intermediate media such as glass substrates for heat transfer, avoiding uneven heat transfer caused by the deformation of the intermediate media, and effectively improving the crystallization quality of the perovskite layer after annealing treatment. By providing a rough layer on the side of the carrier table facing the radiation light source, when the radiation light irradiates the rough surface of the rough layer, part of the radiation light will be attenuated, and the attenuated radiation light is scattered in all directions. At least part of the radiation light scattered by the rough layer is directed towards the perovskite layer and oscillates repeatedly, so that the optical path of this part of the radiation light in the perovskite layer is significantly increased, increasing the absorption amount of the perovskite layer for the radiation light, thereby improving the utilization rate of the radiation light and improving the crystallization quality. Description of the Drawings

[0031] Figure 1 is a schematic structural diagram of the annealing device according to an embodiment of the present invention;

[0032] Figure 2 is a schematic structural view of an annealing device according to another embodiment of the present invention;

[0033] Figure 3 is the absorption spectra of Example 1, Comparative Example 1 and Comparative Example 2 of the embodiments of the present invention;

[0034] Figure 4 is the absorption spectra of Example 2, Comparative Example 1 and Comparative Example 2 of the embodiments of the present invention;

[0035] Figure 5 is the absorption spectra of Example 3, Comparative Example 1 and Comparative Example 2 of the embodiments of the present invention;

[0036] Figure 6 is the absorption spectra of Example 4 and Comparative Example 1 of the embodiments of the present invention;

[0037] Figure 7 is the absorption spectra of Example 5 and Comparative Example 1 of the embodiments of the present invention;

[0038] Figure 8 is the 9-point absorption spectra of Example 6 of the embodiments of the present invention;

[0039] Figure 9 is the 9-point absorption spectra of Comparative Example 3 of the embodiments of the present invention.

[0040] In the figure: 1, radiation light source; 2, carrier table; 3, rough layer; 4, spacing; 5, target material; 51, perovskite layer; 52, substrate. Detailed Embodiments

[0041] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this invention will be more complete and comprehensive, and will fully convey the concept of the example embodiments to those skilled in the art. Like reference numerals in the figures denote like or similar structures and thus their repetitive description will be omitted.

[0042] The words expressing positions and directions described in the present invention are all illustrated by taking the accompanying drawings as examples, but can be changed according to needs, and all the changes made are included in the protection scope of the present invention.

[0043] As Figure 1 and Figure 2As shown, the present invention provides an annealing device for annealing a target material 5. The target material 5 has light transmissivity such that light can pass through the target material 5. The target material 5 can be a substrate 52 coated with a perovskite layer 51. The substrate 52 can be a glass substrate or a substrate of other transparent materials. Specifically, the substrate 52 can be FTO (fluorine-doped tin oxide) glass or ordinary glass. Ordinary glass is a common glass without doping or other treatments, and the chemical composition of ordinary glass is Na2SiO3, CaSiO3, SiO2 or Na2O·CaO·6SiO2, etc.; the perovskite layer 51 can specifically be one or more of MAPbI3 perovskite thin film, FAPbI3 perovskite thin film, CsFAPbI3 perovskite thin film. The perovskite layer 51 has light transmissivity and can be formed by coating a liquid perovskite precursor solution onto the substrate 52, and the perovskite layer 51 can be preliminarily desolvated in advance to form a transparent intermediate phase thin film. The annealing device is specifically used to anneal the perovskite layer 51 in the target material 5 to prepare the perovskite layer 51 into a required perovskite layer. The required perovskite layer is a layer structure in which the perovskite layer 51 absorbs energy and condenses from a liquid state to a solid state to form an opaque layer. The annealing device includes a radiation light source 1 and a carrier table 2.

[0044] The radiation light source 1 is used to generate radiation light. The radiation light is emitted from the radiation light source 1 towards the perovskite layer 51 of the target material 5. When the radiation light irradiates the perovskite layer 51, the perovskite layer 51 can absorb the energy of the radiation light, so that the radiation light can heat the perovskite layer 51 and anneal the perovskite layer 51. Among them, the radiation light source 1 can be an ultraviolet radiation source such as a mercury lamp or a xenon lamp, and the radiation light can be ultraviolet radiation light; or, the radiation light source 1 can adopt other devices that can be used as a radiation annealing light source, for example, the radiation light source 1 adopts other laser radiation sources or microwave radiation sources such as an infrared radiation source.

[0045] The carrier stage 2 is disposed opposite to the radiation light source 1. The carrier stage 2 can support the substrate 52 in the target material 5 in a contact or non-contact manner. A rough layer 3 is provided on the side of the carrier stage 2 facing the radiation light source 1. The target material 5 can be disposed between the rough layer 3 and the radiation light. When the radiation light source 1 generates radiation light, the radiation light is irradiated toward the target material 5. When the radiation light irradiates the target material 5, the perovskite layer 51 of the target material 5 hardly absorbs the radiation light, and the substrate 52 does not absorb the radiation light. Therefore, only a small part of the radiation light is absorbed by the perovskite layer 51 to be used as an energy source for annealing the perovskite layer 51, and most of the radiation light penetrates the perovskite layer 51 and the substrate 52 of the target material 5 and propagates toward the rough layer 3 of the carrier stage 2. When the radiation light propagates to the rough layer 3, since the surface of the rough layer 3 is uneven, part of the radiation light is reflected along the original path, and part of the radiation light is scattered.

[0046] Among them, the rough layer 3 and the carrier stage 2 can be an integral structure. For example, the carrier stage 2 forms the rough layer 3 through processes such as etching. Alternatively, the rough layer 3 can be a layer of a highly reflective thin film, and the rough layer 3 is attached to the carrier stage 2. For example, the rough layer 3 is formed on the carrier stage 2 by means of sputtering or evaporation. Among them, when the rough layer 3 is a thin film, the material of the thin film can be a metal material, such as one of silver, copper, aluminum, tin, etc.; or, the thin film can also be made of other materials with high reflectivity.

[0047] In some radiation annealing devices, the rough layer 3 is not provided on the carrier stage 2, and the surface of the carrier stage 2 is selected to be a smooth surface. When the radiation light passes through the target material 5 and irradiates the smooth surface, the radiation light is basically reflected along the original path by the smooth surface, and the radiation light reflected by the smooth surface passes through the target material 5 and then dissipates into the environment. The optical path of the radiation light in the perovskite layer 51 of the target material 5 is related to the thickness of the perovskite layer 51. Since the thickness of the perovskite layer 51 is limited, the optical path of the radiation light in the perovskite layer 51 is short, resulting in only part of the radiation light being absorbed by the perovskite layer 51, and the rest of the radiation light being wasted. Among them, the original path of the radiation light is the light illumination path when the radiation light passes through the target material 5 and irradiates the carrier stage 2. The radiation light specifically passes through the target material 5 along a vertical path and irradiates the carrier stage 2, and the radiation light reflected by the carrier stage 2 irradiates the target material 5 along the vertical path.

[0048] In the present application, a rough layer 3 is provided on the side of the carrier 2 facing the radiation light source 1, so that the surface of the rough layer 3 forms a rough surface. When the radiation light is irradiated to the rough surface of the rough layer 3, part of the radiation light will be reflected by the rough layer 3 along the original path, and the reflected radiation light will be emitted toward the target material 5 along the original path and pass through the target material 5, and the optical path of this part of the radiation light in the perovskite layer 51 is relatively short. Part of the radiation light will be attenuated, and the attenuated radiation light will be scattered in all directions. At least part of the radiation light scattered by the rough layer 3 will be emitted to the perovskite layer 51 of the target material 5 and oscillate repeatedly, so that the optical path of this part of the radiation light in the perovskite layer 51 is significantly increased, and the absorption amount of the radiation light by the perovskite layer 51 is increased, thereby improving the utilization rate of the radiation light and the crystallization quality. Among them, the path of the radiation light scattered from the rough layer 3 changes, the scattered radiation light enters the substrate 52 of the target material 5, passes through the substrate 52 and enters the perovskite layer 51, and is reflected by the perovskite layer 51 back to the substrate 52 and toward the rough layer 3; therefore, the radiation light can oscillate repeatedly. Specifically, the radiation light can be vertically directed to the target material 5, and then vertically pass through the perovskite layer 51 and the substrate 52 of the target material 5 and be directed to the rough layer 3. The radiation light is reflected and scattered at the rough layer 3. The reflected radiation light passes through the target material 5 along a vertical path, and the direction of the scattered radiation light changes. The scattered radiation light is directed to the perovskite layer 51 along an inclined path. When the scattered radiation light is directed from the lower surface of the perovskite layer 51 to the upper surface, it will be reflected to the rough layer 3 through the upper surface of the perovskite layer 51. The scattered radiation light repeats between the perovskite layer 51 and the rough layer 3, so that this part of the radiation light oscillates repeatedly.

[0049] The radiation reflected by the rough layer 3 is the mirror reflection component, which can also be called the coherent component, and the radiation scattered by the rough layer 3 is the diffuse component, which can also be called the incoherent component. When the roughness of the rough layer 3 is low, the coherent component is dominant, and the incoherent component is weak. At this time, only a small amount of radiation is scattered by the rough layer 3. When the roughness of the rough layer 3 is high, the incoherent component is dominant, and the coherent component is weak. At this time, a large amount of radiation is scattered by the rough layer 3.

[0050] Reference Figure 1 In some specific embodiments, the rough layer 3 is used to contact the target material 5, so that the support platform 2 can support the substrate 52 of the target material 5 in a contact manner. After the radiation light passes through the target material 5 and irradiates the rough layer 3, at least part of the radiation light scattered by the rough layer 3 re-enters the perovskite layer 51 of the target material 5 and oscillates repeatedly.

[0051] In addition, there may be some scattered radiation rays passing through the substrate 52 and directly radiating to the outside from the substrate 52 without entering the perovskite layer 51. As the roughness of the rough layer 3 increases, the scattering range of the scattered radiation rays generated under the action of the rough layer 3 is also larger. At this time, there are also more radiation rays directly scattered into the environment without entering the perovskite layer 51. Both the wavelength λ of the radiation rays and the roughness of the rough layer 3 affect the scattering of the radiation rays. In order to ensure that the scattered radiation rays under the action of the rough layer 3 can enter the perovskite layer 51 to a greater extent and increase the optical path of the radiation rays in the perovskite layer 51 to a greater extent, so as to ensure the utilization efficiency of the radiation rays, the root mean square δ of the height fluctuation of the rough layer 3 can be greater than 0.4 and less than 0.9, and the surface correlation length of the rough layer 3 is approximately the same as the wavelength of the radiation rays. For example, the surface correlation length of the rough layer 3 is 0.8 to 1.2 times the wavelength of the radiation rays, and the wavelength of the radiation rays can specifically be 200 nm to 2 μm.

[0052] Among them, the root mean square δ of the height fluctuation and the surface correlation length are used to jointly characterize the roughness of the rough layer 3. The root mean square δ of the height fluctuation represents the degree of deviation relative to the average height . .

[0053] In the calculation formula of the root mean square δ of the height fluctuation, is the vertical distance between the highest point and the lower surface of the rough layer 3 in the part of the rough layer 3 below the target material 5, that is, the maximum height of the rough layer 3, is the average value of the heights of each point in the part of the rough layer 3 below the target material 5. When the rough layer 3 is a thin film-like structure with high reflectivity, the lower surface of the rough layer 3 is the contact surface between the rough layer 3 and the carrier 2; when the rough layer 3 and the carrier 2 are an integral structure, the rough layer 3 can be assumed to have the same structure as the thin film-like rough layer 3, and the virtual contact surface between the rough layer 3 and the carrier 2 is the lower surface of the rough layer 3. The surface correlation length represents the density of the surface undulation of the rough layer 3.

[0054] The physical surface height can be approximately regarded as obeying a Gaussian distribution or an exponential distribution. The correlation degree between any two points with a horizontal distance of on the surface of the rough layer 3 is described by the autocorrelation function. The Gaussian distribution correlation function is: , and the exponential distribution function is: . When r = 0, ρ(r) = , as r increases, the value of ρ(r) gradually decreases. When r approaches infinity, ρ(r) approaches 0. When the correlation coefficient ρ(r) drops to When the horizontal interval r value between two points is defined as the surface correlation length .

[0055] When the rough layer 3 in the annealing device contacts the perovskite layer 51 of the target material 5, the annealing device can be used to anneal the target material 5 with a size of 300 mm × 300 mm to 400 mm × 500 mm. That is, in the target material 5, the widths of the substrate 52 and the perovskite layer 51 can both be 300 mm to 400 mm, and the lengths of the substrate 52 and the perovskite layer 51 can both be 300 mm to 500 mm. The thickness of the substrate 52 in the target material 5 can be 2 mm to 3.5 mm, and the thickness of the perovskite layer 51 can be 400 nm to 650 nm.

[0056] Referring to Figure 2 , in some other specific embodiments, the rough layer 3 and the substrate 52 of the target material 5 are spaced apart to form a spaced space 4, so that the carrier table 2 can support the substrate 52 of the target material 5 in a non-contact manner. By spacing the substrate 52 of the target material 5 from the rough layer 3, heat transfer generated when the substrate 52 contacts the rough layer 3 can be avoided, thereby preventing temperature differences at various parts of the substrate 52 and further avoiding affecting the annealing uniformity and annealing quality due to the temperature differences. The radiation light passes through the target material 5, then through the spaced space 4, and irradiates the rough layer 3. At least part of the radiation light scattered under the action of the rough layer 3 passes through the spaced space 4 and then enters the perovskite layer 51 of the target material 5 and oscillates repeatedly. Among them, the carrier table 2 can be provided with an air-floating device for supporting the substrate 52. The substrate 52 of the target material 5 is spaced from the rough layer 3 in an air-floating manner. At this time, the carrier table 2 supports the substrate 52 of the target material 5 in a non-contact manner; or, the carrier table 2 can also be provided with a clamping member, and the substrate 52 of the target material 5 can also be clamped and fixed above the rough layer 3 and spaced from the rough layer 3 by means of a clamping member or the like; at this time, the carrier table 2 supports the substrate 52 of the target material 5 in a contact manner, but only the clamping part of the clamping member of the carrier table 2 contacts the substrate 52, and only a small area between the carrier table 2 and the substrate 52 generates heat transfer, effectively reducing the heat transfer generated when the substrate 52 contacts the carrier table 2 and further preventing temperature differences at various parts of the substrate 52.

[0057] Part of the radiation light scattered under the action of the rough layer 3 may directly radiate to the outside without entering the perovskite layer 51 after passing through the spacer 4 or the substrate 52. As the roughness of the rough layer 3 increases, the scattering range of the scattered radiation light generated under the action of the rough layer 3 is also larger. At this time, there are also more radiation lights directly scattered into the environment and entering the perovskite layer 51. Both the wavelength λ of the radiation light and the roughness of the rough layer 3 will affect the reflection and scattering of the radiation light. In addition, the height of the spacer 4 will also affect the amount of scattered radiation light generated under the action of the rough layer 3 directly entering the environment from the spacer 4 or the substrate 52. To enable the radiation light scattered under the action of the rough layer 3 to enter the perovskite layer 51 to a greater extent and increase the optical path of the radiation light in the perovskite layer 51 to ensure the utilization efficiency of the radiation light, the distance h between the rough layer 3 and the target material 5 can be 1 μm to 100 μm. Preferably, the distance h between the highest point of the rough layer 3 and the substrate 52 along the propagation direction of the radiation light is 1 μm to 100 μm; the root mean square δ of the height fluctuation of the rough layer 3 can be greater than 0.6 and less than 0.8, and the surface correlation length of the rough layer 3 is approximately the same as the wavelength of the radiation light. For example, the surface correlation length of the rough layer 3 is 0.8 to 1.2 times the wavelength of the radiation light, and the wavelength of the radiation light can specifically be 380 nm to 10 μm.

[0058] When the rough layer 3 in the annealing device is spaced from the substrate 52 of the target material 5, the annealing device can be used to anneal the target material 5 with a size of 0.6 m × 1 m to 1.2 m × 2.4 m. That is, in the target material 5, the widths of the substrate 52 and the perovskite layer 51 can both be 0.6 m to 1.2 m, and the lengths of the substrate 52 and the perovskite layer 51 can both be 1 m to 2.4 m. The thickness of the substrate 52 in the target material 5 can be 2 mm to 3.5 mm, and the thickness of the perovskite layer 51 can be 400 to 650 nm.

[0059] The present invention also provides an annealing method, and this annealing method can be executed by using the above annealing device. The annealing method includes step S01 and step S02, and may also include step S03.

[0060] Step S01 includes: The radiation light source 1 generates radiation light that irradiates the perovskite layer 51 of the target material 5. A small part of the radiation light is absorbed by the perovskite layer 51, and most of the radiation light penetrates the perovskite layer 51 and irradiates the rough layer 3. For example, the part of the radiation light that penetrates the perovskite layer 51 and irradiates the rough layer 3 is at least 10 times that of the part of the radiation light directly absorbed by the perovskite layer 51. Among them, the substrate 52 of the target material 5 can be in direct contact with the rough layer 3, and the radiation light sequentially penetrates the perovskite layer 51 and the substrate 52 of the target material 5 and then irradiates the rough layer 3. Or, the target material 5 can be arranged at an interval from the rough layer 3, and an interval space 4 is formed between the target material 5 and the rough layer 3. The radiation light sequentially penetrates the perovskite layer 51 and the substrate 52 of the target material 5 and passes through the interval space 4 and then irradiates the rough layer 3.

[0061] Step S02 includes: The radiation light irradiating the rough layer 3 is scattered and reflected in the rough layer 3, and at least part of the scattered radiation light propagates to the perovskite layer 51 and oscillates repeatedly to increase the optical path of the radiation light in the perovskite layer 51. Among them, when the substrate 52 of the target material 5 is in direct contact with the rough surface, most of the scattered radiation light enters and passes through the substrate 52 to enter the perovskite layer 51 and oscillate repeatedly. Or, when the substrate 52 of the target material 5 is arranged at an interval from the rough layer 3, most of the scattered radiation light passes through the interval space 4 and the substrate 52 to enter the perovskite layer 51 and oscillate repeatedly.

[0062] Step S03 includes: The perovskite layer 51 absorbs the energy of the radiation light and gradually changes from a transparent state to a non-transparent state; before the perovskite layer 51 changes to a non-transparent state, the radiation light generated by the radiation light source 1 passes through the perovskite layer 51 and is scattered by the rough layer 3 to the perovskite layer 51 and oscillates repeatedly; when the perovskite layer 51 changes to a non-transparent state, the radiation light generated by the radiation light source 1 is directly absorbed by the perovskite layer 51, and the radiation light passing through the perovskite layer 51 is reflected or scattered to the perovskite layer 51 by the rough layer 3 and absorbed by the perovskite layer 51.

[0063] When the radiation light passes through the perovskite layer 51, the perovskite layer 51 will absorb part of the radiation light, and part of the radiation light passes through the perovskite layer 51 and the substrate 52 and then irradiates the rough layer 3. The radiation light is scattered at the rough layer 3, and most of the scattered radiation light enters the perovskite layer 51 again and oscillates repeatedly between the perovskite layer 51 and the rough layer 3 to effectively increase the optical path of the radiation light in the perovskite layer 51 and improve the efficiency of radiation annealing treatment of the perovskite layer 51.

[0064] In step S01, when the substrate 52 of the target material 5 abuts against the rough layer 3, the radiation light scattered at the rough layer 3 passes through the substrate 52 and enters the perovskite layer 51. At this time, the power of the radiation light source 1 can be 450 - 550 W, and the scanning speed of the radiation light source 1 can be 1 - 3 mm / s; when there is a gap between the substrate 52 of the target material 5 and the rough layer 3 to form a gap space 4, the radiation light scattered at the rough layer 3 passes through the gap space 4 and the substrate 52 and enters the perovskite layer 51. At this time, the power of the radiation light source 1 can be 0.9 - 1.1 kW, and the scanning speed of the radiation light source 1 can be 5 - 7 mm / s.

[0065] Among them, a transparent intermediate phase thin film is pre - formed in the perovskite layer 51 of the target component. When the radiation light irradiates the perovskite layer 51, part of the radiation light is absorbed by the transparent intermediate phase thin film, and part of the radiation light passes through the transparent intermediate phase thin film and then irradiates the rough layer 3.

[0066] In the existing radiation annealing method, the optical path of the radiation light in the perovskite layer 51 is short, and the perovskite layer 51 can only absorb a small amount of radiation light, and most of the energy of the radiation light is wasted. The annealing method of the present application scatters the radiation light passing through the perovskite layer 51 at the rough layer 3, and at least part of the scattered radiation light can irradiate the target material 5 and oscillate repeatedly, effectively increasing the optical path of the radiation light in the perovskite layer 51, thereby improving the absorption effect of the perovskite layer 51 on the radiation light, improving the energy utilization rate of the radiation light, enabling the perovskite layer 51 to absorb more energy from the radiation light within a certain time, and improving the annealing efficiency and annealing quality. The annealing method of the present application generally only needs 2.5 - 3 min to complete the annealing treatment of the perovskite layer 51.

[0067] In step S03, the perovskite layer 51 absorbs the energy of the radiation light and undergoes drying crystallization. The perovskite formed by crystallization is in an opaque state. As the perovskite layer 51 continuously absorbs the energy of the radiation light, the crystallized part of the perovskite layer 51 continuously increases, causing the perovskite layer 51 to gradually change from a transparent state to an opaque state. When the perovskite layer 51 changes to an opaque state, the perovskite layer 51 is in a partially dried or completely dried state.

[0068] Before the perovskite layer 51 changes to an opaque state, the radiation light can pass through the perovskite layer 51 and the substrate 52 and irradiate the rough layer 3, and then the rough layer 3 scatters the radiation light to the perovskite layer 51. When the perovskite layer 51 changes to an opaque state, the radiation light is directly absorbed by the perovskite layer 51 without passing through the perovskite layer 51, but the radiation light that passed through the perovskite layer 51 before the perovskite layer 51 changes to an opaque state may still exist between the perovskite layer 51 and the rough layer 3, and this part of the radiation light is reflected or scattered by the rough layer 3 to the perovskite layer 51 to be absorbed by the perovskite layer 51.

[0069] The present invention also provides a method for preparing a perovskite layer, which includes step S11, step S12, and step S13.

[0070] Step S11 includes: coating a perovskite precursor liquid on a substrate 52 to form a perovskite layer 51.

[0071] Step S12 includes: performing preliminary desolvation on the perovskite layer 51 to form a transparent intermediate phase thin film of the perovskite layer 51.

[0072] Step S13 includes: annealing the perovskite layer 51 on the substrate 52 by using the above annealing method to obtain the required perovskite layer.

[0073] In step S11, the perovskite precursor liquid can be a perovskite precursor liquid with an active ingredient of CsFAPbIBr or CsFAPbI3, or the perovskite precursor liquid can also be other existing perovskite precursor liquids used for preparing a perovskite layer. The perovskite precursor liquid can be coated on the substrate 52 by means of spin coating, slot coating, or blade coating, etc., to coat and form a liquid film-like perovskite layer 51 on the substrate 52.

[0074] In step S12, the method for performing preliminary desolvation on the perovskite layer 51 can be any one of anti-solvent desolvation, VCD (Vacuum Concentration Drying) desolvation, and air knife desolvation. After preliminary desolvation, part of the solution in the perovskite layer 51 is removed, and thus a transparent intermediate phase thin film is formed inside the perovskite layer 51. Example 1

[0075] Formamidinium iodide, lead iodide, and cesium iodide with a mass ratio of 4.7:13:1 are dissolved in a mixed solution of N,N-dimethylformamide and N-methylpyrrolidone with a volume ratio of 13:1, and the mass fraction is 44% to obtain a perovskite precursor liquid with an active ingredient of CsFAPbI3; the perovskite precursor liquid is coated on the substrate 52 by using a slot coating process to form a perovskite layer 51. Among them, in the slot coating process, the liquid outlet speed of the coating head is 20 μL / s, and the moving speed of the coating head is 28 mm / s; the thickness of the substrate 52 is 2 mm, and the size of the substrate 52 is 300 mm × 300 mm.

[0076] The above perovskite layer 51 is subjected to desolvation operation by using VCD desolvation, where the pressure of the VCD process is 5 Pa and the desolvation time is 30 s.

[0077] The perovskite layer 51 after desolvation is subjected to radiative annealing, specifically, laser annealing can be selected. The laser serves as the radiative light, and the wavelength of the laser is 450 nm. A rough layer 3 is prepared on the aluminum carrier 2 by sputtering. The root mean square δ of the height fluctuation of the rough layer 3 is 0.5, and the surface correlation length is close to the wavelength. Specifically, the surface correlation length is 500 nm. The laser annealing power is 500 W, the scanning speed is 2 mm / s, and the annealing time is 2.5 min. Among them, the substrate 52 abuts against the rough layer 3. Example 2

[0078] This example is basically the same as Example 1, except that in this example, the perovskite layer 51 is desolvated by using an air knife. Specifically, an air knife is suspended behind the coating head and bound to the coating head, and the air knife moves with the coating head. The moving speed of the air knife is specifically 5 mm / s to 50 mm / s, the inlet pressure of the air knife is 0.1 to 0.6 Mpa, and the distance between the air knife outlet and the surface of the substrate 52 is 2 - 30 mm. Example 3

[0079] This example is basically the same as Example 1, except that in this example, the wavelength of the laser is 450 nm, the root mean square δ of the fluctuation of the rough layer 3 is 2, and the surface correlation length is less than the wavelength, and the surface correlation length is 200 nm. Example 4

[0080] This example is basically the same as Example 1, except that in this example, the wavelength of the laser is 300 nm, the root mean square δ of the fluctuation of the rough layer 3 is 0.5, and the surface correlation length is the same as the wavelength, both being 300 nm. Example 5

[0081] This example is basically the same as Example 1, except that in this example, the wavelength of the laser is 1.5 μm, the root mean square δ of the fluctuation of the rough layer 3 is 0.5, and the surface correlation length is the same as the wavelength, both being 1.5 μm. Example 6

[0082] Dissolve formamidinium iodide, lead iodide, and cesium bromide with a mass ratio of 5.93:18.07:1 in a mixed solution of N-N-dimethylformamide and acetonitrile with a volume ratio of 9:1, with a mass fraction of 43.3%, to obtain a perovskite precursor solution with an active ingredient of CsFAPbIBr; coat the perovskite precursor solution on the substrate 52 using a slot coating process to form a perovskite layer 51. Among them, in the slot coating process, the liquid outlet speed of the coating head is 40 μL / s, and the moving speed of the coating head is 60 mm / s; the thickness of the substrate 52 is 2 mm, and the size of the substrate 52 is 0.6 m × 1 m.

[0083] Perform a desolvation operation on the above perovskite layer 51 by means of an air knife desolvation, where the moving speed of the air knife is 10 mm / s, the air inlet pressure of the air knife is 0.5 Mpa, and the distance between the air outlet of the air knife and the surface of the substrate 52 is 3 mm.

[0084] Perform radiative annealing on the desolvated perovskite layer 51. Specifically, a laser annealing method can be selected. The laser is used as the radiative light, and the wavelength of the laser is 1.5 μm. Prepare a rough layer 3 on the carrier 2 made of aluminum by sputtering. The root mean square height fluctuation δ of the rough layer 3 is 0.7, and the surface correlation length is the same as the wavelength, both being 1.5 μm. The laser annealing power is 1 kW, the scanning speed is 6 mm / s, and the annealing time is 3 min. Among them, the substrate 52 is spaced from the rough layer 3 through an air bearing design, and the distance between the substrate 52 and the rough layer 3 is 80 μm. Comparative Example 1

[0085] This example is basically the same as Example 1, except that in this example, the perovskite layer 51 is annealed by a hot plate annealing method, the annealing temperature is 130 °C, and the annealing time is 15 min. Comparative Example 2

[0086] This example is basically the same as Example 1, except that in this example, the laser wavelength is 450 nm. No rough layer 3 is formed on the surface of the carrier 2, that is, the root mean square height fluctuation δ of the surface of the carrier 2 is 0.08, and the surface correlation length is much larger than the wavelength, and the surface correlation length is specifically 1 mm. Comparative Example 3

[0087] This example is basically the same as Example 6, except that in this example, the substrate 52 is in direct contact with the rough layer 3.

[0088] Perform ultraviolet-visible absorption characterization on the perovskite layers prepared in the above examples and comparative examples to obtain the corresponding spectral information. In the absorption spectrum, the horizontal axis is the wavelength, with the unit of nm, and the vertical axis is the absorbance, with the unit of L / (g·cm).

[0089] Reference Figure 3 , Figure 3 is the spectral information of the perovskite layers prepared in Example 1, Comparative Example 1, and Comparative Example 2. It can be seen that the ultraviolet-visible light absorption of Example 1 is comparable to that of Comparative Example 1, and the ultraviolet-visible light absorption of Example 1 is slightly stronger than that of Comparative Example 1. Compared with the hot plate annealing method in Comparative Example 1, the present application uses radiation light for annealing treatment, which greatly shortens the annealing time, and the quality of the perovskite layer prepared after annealing treatment is also better. The ultraviolet-visible light absorption of Example 1 is significantly better than that of Comparative Example 2. It can be seen that by setting the rough layer 3, under the same radiation light and the same annealing time, the annealing efficiency and annealing quality can be significantly improved, so that the prepared perovskite layer has a higher light utilization rate.

[0090] Reference Figure 4 , Figure 4 is the spectral information of the perovskite layers prepared in Example 2, Comparative Example 1, and Comparative Example 2. It can be seen that the ultraviolet-visible light absorption of Example 2 is comparable to that of Comparative Example 1, and the ultraviolet-visible light absorption of Example 2 is slightly stronger than that of Comparative Example 1. The ultraviolet-visible light absorption of Example 2 is significantly better than that of Comparative Example 2.

[0091] Reference Figure 5 , Figure 5 is the spectral information of the perovskite layers prepared in Example 3, Comparative Example 1, and Comparative Example 2. The ultraviolet-visible light absorption of Example 3 is weaker than that of Comparative Example 1, and the ultraviolet-visible light absorption of Example 3 is better than that of Comparative Example 2. It can be seen that when the root mean square of height fluctuation δ is set larger so that the roughness of the rough surface is higher, the effect of annealing the perovskite layer 51 with the scattered radiation light is slightly worse.

[0092] Reference Figure 6 and Figure 7 , Figure 6 is the spectral information of the perovskite layers prepared in Example 4 and Comparative Example 1, Figure 7 is the spectral information of the perovskite layers prepared in Example 5 and Comparative Example 1. It can be seen that the ultraviolet-visible light absorption of Example 4 and Example 5 is comparable to that of Comparative Example 1, and the ultraviolet-visible light absorption of Example 4 and Example 5 is slightly stronger than that of Comparative Example 1 respectively.

[0093] The above Figures 3 to 7 In, the spectral information is the average value of the absorbance corresponding to each wavelength measured at multiple places for the corresponding example or comparative example. By measuring the average value of the absorbance corresponding to different wavelengths to obtain Figures 6 to 9 the spectral information in.

[0094] Reference Figures 8 to 9, Figure 8 It is the spectral information obtained by measuring 9 points on the perovskite layer prepared in Example 6 respectively. Figure 9 It is the spectral information obtained by measuring 9 points on the perovskite layer prepared in Comparative Example 3 respectively. It can be seen that although the ultraviolet-visible light absorption of Example 6 is comparable to that of Comparative Example 3, the uniformity of the ultraviolet-visible light absorption of Comparative Example 3 is significantly worse than that of Example 6. Specifically, after measurement, the uniformity of the ultraviolet-visible light absorption of Example 6 is 1.61%, and the uniformity of the ultraviolet-visible light absorption of Comparative Example 3 is 9.31%. Among them, the uniformity of the ultraviolet-visible light absorption represents the uniformity of the ultraviolet-visible light absorption at each part of the perovskite layer. The smaller the uniformity, the more uniform the ultraviolet-visible light absorption.

[0095] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Without departing from the principle and purpose of the present invention, those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the invention, and all these changes should fall within the protection scope of the claims of the present invention.

Claims

1. An annealing device for heating and crystallizing a perovskite layer (51), characterized in that Comprising: A radiation light source (1) for generating radiation light rays for heating a perovskite layer (51); A carrier stage (2) disposed opposite to the radiation light source (1) and for supporting a substrate (52) attached with the perovskite layer (51); A rough layer (3) is provided on a side of the carrier stage (2) facing the radiation light source (1), the rough layer (3) is located on a side of the perovskite layer (51) facing away from the radiation light source (1), and the rough layer (3) receives the radiation light rays penetrating the perovskite layer (51) and scatters at least part of the radiation light rays to the perovskite layer (51) and oscillates repeatedly to increase the optical path of the radiation light rays within the perovskite layer (51).

2. The annealing device according to claim 1, wherein The rough layer (3) is for contacting with the substrate (52), and the carrier stage (2) supports the substrate (52) in a contact manner. The root mean square of the height fluctuation of the rough layer (3) is greater than 0.4 and less than 0.9, and the surface correlation length of the rough layer (3) is 0.8 to 1.2 times the wavelength of the radiation light rays; the wavelength of the radiation light rays is 200 nm to 2 μm.

3. The annealing device according to claim 2, wherein, The thickness of the substrate (52) is 2 mm to 3.5 mm, the size of the substrate (52) is 300 mm × 300 mm to 400 mm × 500 mm, and the substrate (52) is a glass substrate.

4. The annealing device according to claim 1, characterized in that, The rough layer (3) is spaced from the substrate (52), and the carrier stage (2) supports the substrate (52) in a non-contact manner. The spacing between the rough layer (3) and the substrate (52) is 1 μm to 100 μm; the root mean square of the height fluctuation of the rough layer (3) is greater than 0.6 and less than 0.8, and the surface correlation length of the rough layer (3) is 0.8 to 1.2 times the wavelength of the radiation light rays; the wavelength of the radiation light rays is 380 nm to 10 μm.

5. The annealing device according to claim 4, characterized in that, The thickness of the substrate (52) is 2 mm to 3.5 mm, the size of the substrate (52) is 0.6 m × 1 m to 1.2 m × 2.4 m, and the substrate (52) is a glass substrate.

6. The annealing device according to claim 3 or 5, characterized in that, The substrate (52) is FTO glass or ordinary glass; the perovskite layer (51) is one or more of a MAPbI3 perovskite thin film, a FAPbI3 perovskite thin film, and a CsFAPbI3 perovskite thin film.

7. The annealing device according to claim 1, wherein, The rough layer (3) and the carrier stage (2) are of an integral structure, or the rough layer (3) is a thin film attached to the surface of the carrier stage (2), and the material of the thin film is a metal material.

8. The annealing device according to claim 1, characterized in that, The rough layer (3) is formed on the carrier stage (2) by etching, sputtering, or evaporation.

9. An annealing method, characterized in that, The annealing method is applied to the annealing device according to any one of claims 1 to 8, and the annealing method includes: The radiation light source (1) generates radiation light rays that irradiate the perovskite layer (51). Part of the radiation light rays are absorbed by the perovskite layer (51), and part of the radiation light rays penetrate the perovskite layer (51) and the substrate (52) and irradiate the rough layer (3); The radiation light irradiated onto the rough layer (3) is scattered and reflected in the rough layer (3), and at least part of the scattered radiation light propagates to the perovskite layer (51) and oscillates repeatedly to increase the optical path of the radiation light within the perovskite layer (51).

10. The annealing method according to claim 9, wherein The perovskite layer (51) is pre-formed with a transparent intermediate phase thin film, and when the radiation light generated by the radiation light source (1) passes through the perovskite layer (51), the transparent intermediate phase thin film absorbs part of the radiation light; wherein, the radiation light is directed at the target material (5).

11. The annealing method according to claim 10, wherein, The substrate (52) abuts against the rough layer (3), and the radiation light scattered at the rough layer (3) passes through the substrate (52) to enter the perovskite layer (51). Among them, the power of the radiation light source (1) is 450 - 550 W, and the scanning speed is 1 - 3 mm / s; Or, the substrate (52) is spaced from the rough layer (3) to form a spaced space (4), and the radiation light scattered at the rough layer (3) passes through the spaced space (4) and the substrate (52) to enter the perovskite layer (51). Among them, the power of the radiation light source (1) is 0.9 - 1.1 kW, and the scanning speed is 5 - 7 mm / s.

12. The annealing method according to claim 9, characterized in that, Further comprising: The perovskite layer (51) absorbs the energy of the radiation light and gradually changes from a transparent state to an opaque state; Before the perovskite layer (51) changes to an opaque state, the radiation light generated by the radiation light source (1) passes through the perovskite layer (51) and is scattered to the perovskite layer (51) by the rough layer (3) and oscillates repeatedly; when the perovskite layer (51) changes to an opaque state, the radiation light generated by the radiation light source (1) is directly absorbed by the perovskite layer (51), and the radiation light passing through the perovskite layer (51) is reflected or scattered to the perovskite layer (51) by the rough layer (3) and is absorbed by the perovskite layer (51).

13. A method for preparing a perovskite layer, characterized in that, Comprising: Coating a perovskite precursor solution on the substrate (52) to form a perovskite layer (51); Performing preliminary desolvation on the perovskite layer (51) to enable the perovskite layer (51) to form a transparent intermediate phase thin film; Performing an annealing treatment on the perovskite layer (51) on the substrate (52) by using the annealing method according to any one of claims 9 to 12.

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