Auxiliary preparation method of high-quality perovskite thin film and perovskite thin film battery assembly

Abstract

The invention discloses an auxiliary preparation method of a high-quality perovskite thin film and a perovskite thin film battery assembly. The method comprises the following steps: S1, providing a glass substrate; s2, preparing a transparent conductive layer on the light emitting surface of the glass substrate; s3, preparing a first charge transport layer on the transparent conductive layer; s4, preparing a template layer on the first charge transport layer, wherein the template layer is provided with a plurality of hole structures, so that the template layer forms a latticed structure; s5, coating the template layer with a perovskite precursor solution, performing primary annealing crystallization and secondary annealing crystallization to prepare a high-quality perovskite thin film; wherein the template layer can be decomposed to be removed or reserved after the perovskite thin film is prepared. The perovskite thin film battery assembly comprises a perovskite thin film; the second charge transport layer is stacked on the perovskite thin film; a back electrode stacked on the second charge transport layer; the packaging adhesive film is stacked on the back electrode; and the back plate glass is arranged on the packaging adhesive film in a laminated manner.

Description

Technical Field

[0001] The present invention relates to the technical field of perovskite solar cells, and particularly to an auxiliary preparation method for a high-quality perovskite thin film and a perovskite thin film battery module. Background Art

[0002] In recent years, perovskite solar cells (PSCs) have made remarkable progress in optoelectronic performance and attracted wide attention. In the past decade, the power conversion efficiency (PCE) of perovskite solar cells (PSCs) has also been greatly improved.

[0003] However, due to the high sensitivity of the perovskite (PVK) thin film to the substrate matrix, challenges still exist in the rapid growth process and quality of perovskite crystals. This sensitivity can lead to excessive crystallization nucleation and the formation of poor defects in perovskite, thus affecting the power conversion efficiency of perovskite solar cells. Summary of the Invention

[0004] The purpose of the present invention is to address the problem that in the current preparation process of perovskite thin films, due to the high sensitivity of the thin film to the substrate matrix, the growth of perovskite crystals will result in excessive crystallization nucleation and the formation of poor defects, thereby causing the power conversion efficiency of perovskite solar cells to be not high. The present invention proposes an auxiliary preparation method for a high-quality perovskite thin film, which overcomes the problems of excessive crystallization nucleation and the formation of poor defects during the growth process of perovskite crystals, thereby achieving the purpose of improving the power conversion efficiency of perovskite solar cells.

[0005] To achieve the above purpose, the present invention is implemented through the following technical solutions:

[0006] The present invention provides an auxiliary preparation method for a high-quality perovskite thin film, which is characterized in that the method comprises the following steps:

[0007] S1. Provide a glass substrate having opposite light incident and light exiting surfaces;

[0008] S2. Prepare a transparent conductive layer on the light exiting surface of the glass substrate;

[0009] S3. Prepare a first charge transport layer on the transparent conductive layer;

[0010] S4. Prepare a template layer for assisting the growth of perovskite crystals on the first charge transport layer, and the template layer has a plurality of hole structures so that the template layer forms a grid-like structure;

[0011] S5. Coat a perovskite precursor solution on the grid-like template layer, and then perform primary annealing crystallization and secondary annealing crystallization to obtain a high-quality perovskite thin film;

[0012] Among them, the template layer can be decomposed and removed or retained after the perovskite thin film is prepared.

[0013] Specifically, in this preparation method of the present invention, by setting the template layer, the growth process of perovskite grains can be templated and controlled, so as to achieve the purpose of improving the quality of the perovskite thin film and enhancing the conversion efficiency of the perovskite thin film battery. In the present invention, the perovskite crystal can be guided by the template layer to crystallize and grow into a highly dense perovskite thin film.

[0014] Furthermore, an auxiliary preparation method for a high-quality perovskite thin film: Step S2 is to prepare a transparent conductive layer with a thickness of 150 - 200 nm on the light-emitting surface of the cleaned glass substrate by magnetron sputtering.

[0015] Furthermore, an auxiliary preparation method for a high-quality perovskite thin film: Step S3 is to coat a material for forming the first charge transport layer on the transparent conductive layer by sputtering, spin coating, evaporation coating, doctor blade coating or slot die coating, and then anneal at 120 - 160 °C for 15 - 45 minutes to obtain a first charge transport layer with a thickness of 40 - 100 nm.

[0016] Furthermore, an auxiliary preparation method for a high-quality perovskite thin film: Step S4 is to coat a material for forming the template layer on the first charge transport layer by a dry method, a wet method or a dry-wet mixed method, and then heat and flash evaporate to form the template layer; the perimeter of the pore structure in the template layer is 300 - 600 nm; the thickness of the template layer is not less than the thickness of the perovskite thin film.

[0017] Even further, an auxiliary preparation method for a high-quality perovskite thin film: The material for forming the template layer in Step S4 is selected as resin.

[0018] Furthermore, an auxiliary preparation method for a high-quality perovskite thin film: In Step S5, the temperature of the first annealing crystallization is 65 - 75 °C, the time of the first annealing is 1 - 3 minutes, the temperature of the second annealing crystallization is 90 - 110 °C, and the annealing time is 20 - 35 minutes.

[0019] Furthermore, an auxiliary preparation method for a high-quality perovskite thin film: In Step S5, the thickness of the perovskite thin film is 300 - 600 nm.

[0020] The present invention also provides a perovskite thin film battery assembly, which is characterized in that the perovskite thin film battery assembly includes:

[0021] The perovskite thin film prepared by the above preparation method;

[0022] A second charge transport layer, which is laminated on the perovskite thin film;

[0023] A back electrode, which is stacked on the second charge transport layer;

[0024] An encapsulation film, which is stacked on the back electrode;

[0025] And a backplane glass, which is stacked on the encapsulation film.

[0026] Furthermore, a perovskite thin film battery module: the thickness of the second charge transport layer is set to be 40 - 100 nm.

[0027] Furthermore, a perovskite thin film battery module: the thickness of the back electrode is set to be 50 - 120 nm.

[0028] Advantages of the present invention:

[0029] (1) Aiming at the problem that during the preparation of perovskite thin films at present, due to the high sensitivity of the thin films to the substrate matrix, the growth of perovskite crystals will result in over - crystallization nucleation and formation of poor defects. The present invention proposes an auxiliary preparation method for high - quality perovskite thin films. The perovskite thin films prepared by this method have high film - forming quality and overcome the above - mentioned problems of over - crystallization nucleation and formation of poor defects. The preparation method proposed by the present invention is a method for preparing perovskite thin films using the template method, that is, a grid - shaped template layer is introduced before the preparation of perovskite thin films. The template layer can induce the vertical growth of perovskite crystals within the pore structure of the template layer. This method can achieve the purpose of preparing high - quality and uniform perovskite thin films, thereby further improving the photoelectric conversion efficiency of perovskite thin film solar cells.

[0030] (2) The method of the present invention provides a unique preparation method for perovskite thin films. A template layer is prepared before the perovskite thin film layer. The main function of the template is to limit the growth of perovskite crystals in the horizontal direction and guide their vertical growth to prepare a vertically penetrating perovskite grain structure, which will not affect the perovskite thin film. The perovskite thin films prepared by this method have perovskite grains penetrating up and down, with better charge conduction ability, which can reduce the internal efficiency loss of the thin film battery and further improve the photoelectric conversion efficiency of perovskite solar cells.

[0031] (3) In the process of the present invention, a two - step annealing crystallization process is adopted. The temperature of the first annealing crystallization is lower and the time is shorter, which can make the perovskite crystals start to grow and fill the pore structure of the template layer. Then, through the combined action of the secondary annealing crystallization process and the template layer, the perovskite crystals grow uniformly, forming a more uniform perovskite thin film. If only one - step annealing crystallization is carried out, the uniformity of the perovskite thin film will be affected, thus affecting the photoelectric conversion efficiency of perovskite solar cells.

[0032] (4) Before the process of preparing the perovskite thin film provided by the present invention, a template layer with a grid structure is prepared in advance to provide a template for the growth of perovskite grains, guide their growth in the vertical direction, so as to prepare a vertically penetrating perovskite thin grain structure, which is beneficial to improving the surface uniformity of perovskite grains, their own charge transport ability, increasing the grain size, reducing grain boundaries, and thus improving the photoelectric conversion efficiency of the battery. Detailed implementation manners

[0033] The technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention. In the description of the present invention, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. Moreover, the terms "first", "second", etc. are used to distinguish similar objects and do not have to be used to describe a specific order or sequence.

[0034] Embodiment 1

[0035] Embodiment 1 of the present invention provides an auxiliary preparation method for a high-quality perovskite thin film, and the method includes the following specific steps:

[0036] S1. Provide a glass substrate having an incident light surface and an outgoing light surface opposite to each other, clean the glass substrate, and then place it in an oven at 70 °C for drying;

[0037] S2. Prepare a transparent conductive layer with a thickness of 180 nm on the outgoing light surface of the cleaned glass substrate by magnetron sputtering;

[0038] S3. Coat a material for forming a first charge transport layer on the transparent conductive layer by spin coating, and then anneal it at 150 °C for 30 minutes to obtain a first charge transport layer with a thickness of 80 nm; wherein, the material for forming the first charge transport layer uses a NiOx solution;

[0039] S4. Coat a material for forming a template layer on the first charge transport layer by wet coating, and then heat and flash to remove the solvent to form the template layer. The perimeter of the hole structure in the template layer is 600 nm, and the thickness of the template layer is not less than the thickness of the perovskite thin film;

[0040] Among them, the material for forming the template layer is selected as a liquid transparent resin;

[0041] S5. Coating a perovskite precursor solution on the grid-shaped template layer, then performing a first annealing crystallization at 70 °C for 1 minute, and then performing a second annealing crystallization at 100 °C for 30 minutes to obtain a high-quality perovskite thin film with a thickness of 500 nm; the template layer can be retained after the preparation of the perovskite thin film is completed;

[0042] Among them, the perovskite precursor solution is obtained by mixing lead iodide, formamidinium iodide, and chloroformamidinium in a molar ratio of 1:1:0.05 and dissolving them in a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide with a volume ratio of 8:1.

[0043] In Example 1, before preparing the perovskite thin film, a grid-shaped template layer is prepared in advance. The template layer provides a template for the growth of perovskite grains, guiding their growth in the vertical direction to prepare a vertically penetrating perovskite thin grain structure. This is beneficial to improving the surface uniformity of perovskite grains, their own charge transport ability, increasing the grain size, and reducing grain boundaries, thereby improving the photoelectric conversion efficiency of the perovskite thin film battery.

[0044] Example 2

[0045] This Example 2 provides an auxiliary preparation method for a high-quality perovskite thin film. The method includes the following specific steps:

[0046] S1. Providing a glass substrate having opposite light incident and light exiting surfaces, cleaning the glass substrate, and then drying it in an oven at 70 °C;

[0047] S2. Preparing a transparent conductive layer with a thickness of 150 nm on the light exiting surface of the cleaned glass substrate by magnetron sputtering;

[0048] S3. Coating a material for forming a first charge transport layer on the transparent conductive layer by spin coating, and then annealing at 130 °C for 40 minutes to obtain a first charge transport layer with a thickness of 45 nm; among them, the material for forming the first charge transport layer uses a NiOx solution;

[0049] S4. Coating a material for forming a template layer on the first charge transport layer by wet coating, and then heating and flash evaporation to form the template layer. The perimeter of the hole structure in the template layer is 400 nm, and the thickness of the template layer is not less than the thickness of the perovskite thin film;

[0050] Among them, the material for forming the template layer is selected as a liquid transparent resin;

[0051] S5. Coat the perovskite precursor solution on the grid-like template layer, then perform primary annealing crystallization at 65 °C for 2 minutes, and then perform secondary annealing crystallization at 95 °C for 25 minutes to obtain a high-quality perovskite thin film with a thickness of 400 nm; the template layer can be removed after the perovskite thin film is prepared.

[0052] Example 3

[0053] This Example 3 provides an auxiliary preparation method for a high-quality perovskite thin film, and this method includes the following specific steps:

[0054] S1. Provide a glass substrate with opposite light incident surface and light emitting surface, clean the glass substrate, and then place it in an oven at 70 °C for drying;

[0055] S2. Prepare a transparent conductive layer with a thickness of 200 nm on the light emitting surface of the cleaned glass substrate by magnetron sputtering;

[0056] S3. Coat the material for forming the first charge transport layer on the transparent conductive layer by spin coating, and then anneal at 160 °C for 20 minutes to obtain the first charge transport layer with a thickness of 100 nm; among them, the material for forming the first charge transport layer uses NiOx solution;

[0057] S4. Coat the material for forming the template layer on the first charge transport layer by wet coating, and then heat and flash evaporate to form the template layer. The perimeter of the hole structure in the template layer is 500 nm, and the thickness of the template layer is not less than the thickness of the perovskite thin film;

[0058] Among them, the material for forming the template layer is selected as liquid transparent resin;

[0059] S5. Coat the perovskite precursor solution on the grid-like template layer, then perform primary annealing crystallization at 75 °C for 2 minutes, and then perform secondary annealing crystallization at 105 °C for 30 minutes to obtain a high-quality perovskite thin film with a thickness of 500 nm; the template layer can be retained after the perovskite thin film is prepared.

[0060] Example 4

[0061] This Example 4 provides a perovskite thin film battery component, and this thin film battery component includes:

[0062] The perovskite thin film prepared by the preparation method of the above Example 1;

[0063] A second charge transport layer, which is stacked on the perovskite thin film, and the thickness of the second charge transport layer is set to 60 nm. The second charge transport layer can be formed by evaporation;

[0064] The back electrode is stacked on the second charge transport layer. The thickness of the back electrode is set to 80 nm. The material of the back electrode can be selected as metallic silver with high conductivity and good stability. The back electrode can be formed by evaporation to ensure good ohmic contact with the second charge transport layer, thereby improving the charge transport efficiency of the battery;

[0065] The encapsulation film is stacked on the back electrode;

[0066] And the backplane glass is stacked on the encapsulation film.

[0067] Comparative Example 1

[0068] Comparative Example 1 provides a method for preparing a perovskite thin film, which includes the following specific steps:

[0069] (1) Provide a glass substrate with opposite light incident surface and light emitting surface, clean the glass substrate, and then place it in an oven at 70 °C for drying;

[0070] (2) Prepare a transparent conductive layer with a thickness of 180 nm on the light emitting surface of the cleaned glass substrate by magnetron sputtering;

[0071] (3) Coat the material for forming the first charge transport layer on the transparent conductive layer by spin coating, and then anneal at 150 °C for 30 minutes to obtain a first charge transport layer with a thickness of 80 nm; among them, the material for forming the first charge transport layer uses NiOx solution;

[0072] (4) Coat the perovskite precursor solution on the first charge transport layer, then perform a first annealing crystallization at 70 °C for 1 minute, and then perform a second annealing crystallization at 100 °C for 30 minutes to obtain a perovskite thin film with a thickness of 500 nm.

[0073] The difference between Comparative Example 1 and Example 1 is that the template layer in Example 1 is not introduced in the preparation method of Comparative Example 1, and the other conditions are the same as those in Example 1.

[0074] Comparative Example 2

[0075] Comparative Example 2 provides a method for preparing a perovskite thin film, which includes the following specific steps:

[0076] (1) Provide a glass substrate with opposite light incident surface and light emitting surface, clean the glass substrate, and then place it in an oven at 70 °C for drying;

[0077] (2) Prepare a transparent conductive layer with a thickness of 180 nm on the light emitting surface of the cleaned glass substrate by magnetron sputtering;

[0078] (3) A material for forming the first charge transport layer is spin-coated on the transparent conductive layer, and then annealed at 150 °C for 30 minutes to obtain a first charge transport layer with a thickness of 80 nm; among them, the material for forming the first charge transport layer uses a NiOx solution;

[0079] (4) A material for forming the template layer is wet-coated on the first charge transport layer, and then heated and flash-evaporated to form the template layer. The perimeter of the pore structure in the template layer is 600 nm, and the thickness of the template layer is not less than the thickness of the perovskite thin film; among them, the material for forming the template layer is selected as a liquid transparent resin;

[0080] (5) A perovskite precursor solution is coated on the grid-shaped template layer, and then annealed and crystallized at 100 °C for 30 minutes to obtain a high-quality perovskite thin film with a thickness of 500 nm; the template layer can be retained after the perovskite thin film is prepared.

[0081] The difference between Comparative Example 2 and Example 1 is that in Comparative Example 2, the two-step annealing and crystallization process is not adopted, and the rest is the same as in Example 1.

[0082] Comparative Example 3

[0083] Comparative Example 3 provides a perovskite thin film battery module, which includes:

[0084] The perovskite thin film prepared by the preparation method of the above Comparative Example 1;

[0085] A second charge transport layer, which is laminated on the perovskite thin film. The thickness of the second charge transport layer is set to 60 nm, and the second charge transport layer can be formed by evaporation;

[0086] A back electrode, which is laminated on the second charge transport layer. The thickness of the back electrode is set to 80 nm. The material of the back electrode can be selected as metal silver with high conductivity and good stability. The back electrode can be formed by evaporation to ensure a good ohmic contact between it and the second charge transport layer, thereby improving the charge transport efficiency of the battery;

[0087] An encapsulation film, which is laminated on the back electrode;

[0088] And a backplane glass, which is laminated on the encapsulation film.

[0089] The difference between Comparative Example 3 and Example 4 is that the perovskite thin film battery module of Comparative Example 3 is assembled with the perovskite thin film prepared in Comparative Example 1, while the perovskite thin film battery module of Example 4 is assembled with the perovskite thin film prepared in Example 1, and the rest is the same.

[0090] Comparative Example 4

[0091] Comparative Example 4 provides a perovskite thin film battery module, which includes:

[0092] The perovskite thin film prepared by the preparation method of the above Comparative Example 2;

[0093] A second charge transport layer, which is stacked on the perovskite thin film. The thickness of the second charge transport layer is set to 60 nm, and the second charge transport layer can be formed by evaporation;

[0094] A back electrode, which is stacked on the second charge transport layer. The thickness of the back electrode is set to 80 nm. The material of the back electrode can be selected as metal silver with high conductivity and good stability. The back electrode can be formed by evaporation to ensure good ohmic contact with the second charge transport layer, thereby improving the charge transport efficiency of the battery;

[0095] An encapsulation film, which is stacked on the back electrode;

[0096] And a backplane glass, which is stacked on the encapsulation film.

[0097] The difference between Comparative Example 4 and Example 4 is that the perovskite thin film battery module of Comparative Example 4 is assembled with the perovskite thin film prepared in Comparative Example 2, while the perovskite thin film battery module of Example 4 is assembled with the perovskite thin film prepared in Example 1, and the rest are the same.

[0098] Test:

[0099] Perform electrical performance tests on the perovskite thin film battery modules of the above Example 4, Comparative Example 3 and Comparative Example 4. The test results are shown in the following table:

[0100]

[0101]

[0102] It can be seen from the test results of Example 4 and Comparative Example 3 in the table that by introducing a template layer before the preparation of the perovskite thin film in the present invention, it can limit the growth of perovskite crystals in the horizontal direction and guide the crystals to grow in the vertical direction, so as to prepare a vertically penetrating perovskite grain structure, so that the perovskite thin film grains penetrate up and down, having a more excellent charge conduction ability. Therefore, compared with the module of Comparative Example 3, the perovskite thin film battery module of Example 4 has a significant improvement in conversion efficiency. It can be seen from the test results of Example 4 and Comparative Example 4 in the table that the two-step annealing crystallization process adopted in the process of the present invention can also make the film formation quality of the perovskite thin film better. The perovskite thin film prepared by two-step annealing crystallization has a higher conversion efficiency of the prepared thin film battery module.

[0103] The above-mentioned preferred embodiments of the present invention are only used to explain the present invention and are not used to limit the present invention. Any obvious changes or variations derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A method for auxiliary preparation of high-quality perovskite film, characterized in that: The method comprises the following steps: S1. providing a glass substrate having a light incident surface and a light emitting surface opposite to each other; S2, preparing a transparent conductive layer on the light emitting surface of the glass substrate; S3, preparing a first charge transport layer on the transparent conductive layer; S4, preparing a template layer for assisting the growth of perovskite crystals on the first charge transport layer, wherein the template layer has a plurality of hole structures so that the template layer forms a grid-like structure; S5, coating a perovskite precursor solution on the grid-shaped template layer, and then performing a first annealing crystallization and a second annealing crystallization to obtain a high-quality perovskite film; The template layer can be decomposed, removed or retained after the perovskite film is prepared.

2. The auxiliary preparation method of a high-quality perovskite film according to claim 1, characterized in that: Step S2: a transparent conductive layer with a thickness of 150-200 nm is prepared on the light-emitting surface of the cleaned glass substrate by magnetron sputtering.

3. The auxiliary preparation method of a high-quality perovskite film according to claim 1, characterized in that: Step S3: coating the material for forming the first charge transport layer on the transparent conductive layer by sputtering, spin coating, evaporation, blade coating or slit coating, and then annealing at 120-160° C. for 15-45 minutes to obtain a first charge transport layer with a thickness of 40-100 nm.

4. The auxiliary preparation method of a high-quality perovskite film according to claim 1, characterized in that: Step S4: coating a material for forming a template layer on the first charge transport layer by a dry method, a wet method or a dry-wet mixed method, and then heating and flash evaporating to form the template layer; the circumference of the hole structure in the template layer is 300 to 600 nm; the thickness of the template layer is not less than the thickness of the perovskite film.

5. The auxiliary preparation method of a high-quality perovskite film according to claim 4, characterized in that: The material used to form the template layer in step S4 is resin.

6. The auxiliary preparation method of a high-quality perovskite film according to claim 1, characterized in that: In step S5, the temperature of the primary annealing crystallization is 65-75° C., the time of the primary annealing is 1-3 minutes, and the temperature of the secondary annealing crystallization is 90-110° C., the time of the annealing is 20-35 minutes.

7. The auxiliary preparation method of a high-quality perovskite film according to claim 1 or 6, characterized in that: The thickness of the perovskite film in step S5 is 300-600 nm.

8. A perovskite thin film battery assembly, characterized in that: The perovskite thin film battery assembly includes: The perovskite film obtained by the preparation method according to any one of claims 1 to 7; A second charge transport layer, which is stacked on the perovskite film; A back electrode, which is stacked on the second charge transport layer; A packaging film, which is stacked on the back electrode; And a back plate glass, which is stacked on the packaging film.

9. A perovskite thin film battery assembly according to claim 8, characterized in that: The thickness of the second charge transport layer is set to be 40-100 nm.

10. A perovskite thin film battery assembly according to claim 8, characterized in that: The thickness of the back electrode is set to be 50-120 nm.

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