Preparation method of nickel oxide film and product and application thereof

Abstract

The invention discloses a preparation method of a nickel oxide film and a product and application thereof, and belongs to the technical field of photovoltaic materials and devices. The preparation method comprises the following steps: providing a homogeneous aqueous solution containing a nickel source compound and basic amino acid, depositing the homogeneous aqueous solution on a to-be-coated surface of a substrate in a chemical bath, forming a nickel hydroxide film layer on the to-be-coated surface in situ, and annealing the nickel hydroxide film layer to generate a nickel oxide film. According to the invention, alkaline amino acid chemical bath deposition is introduced into a nickel source chemical bath aqueous solution, so that not only can multidentate coordination with moderate strength be formed through alkaline amino acid and nickel ions, the nucleation rate of nickel hydroxide be effectively and reasonably adjusted, but also agglomeration of generated nanoparticles can be prevented through a steric hindrance effect, and the nucleation rate of nickel hydroxide can be effectively and reasonably adjusted. And the dispersion effect of the nanoparticles is effectively improved, so that the deposition behavior of the nickel hydroxide nanoparticles is synergistically optimized through the two aspects, and finally controllable preparation of the uniform and compact nickel oxide thin film with good crystallinity is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of photovoltaic materials and devices, and in particular relates to a method for preparing a nickel oxide thin film, a product thereof and an application thereof. Background Art

[0002] Nickel Oxide (NiO x ) has become the most promising hole transport layer material for perovskite solar cells due to its high hole mobility, low manufacturing cost and good stability. However, when nickel oxide nanoparticles are prefabricated by spin coating and other techniques to construct a nickel oxide hole transport layer, the prepared nickel oxide film is prone to uneven thickness, surface morphology defects and poor crystallinity, which is not conducive to the photoelectric conversion and stability of the battery. Therefore, the development and preparation of high-quality nickel oxide films has become a research hotspot.

[0003] At present, the related art discloses that nickel oxide thin film can be prepared by chemical bath deposition. For example, a method for preparing nickel oxide thin film is disclosed in a patent application with publication number CN115101682 A, which introduces ammonium ions into an alkaline nickel-containing chemical bath solution and deposits NiO by chemical bath deposition. x The particles are homogeneously nucleated to form uniform and dense NiO x film.

[0004] However, the existing chemical bath deposition technology for preparing nickel oxide thin films still has some shortcomings, such as: (1) the selected ligands (ammonia, ethanolamine, etc.) have relatively weak complexation with nickel ions, resulting in uneven release of nickel ions during the nucleation process, which makes the uniformity of nickel oxide nucleation need to be improved; (2) the ligand molecular structure is relatively small, which easily leads to the agglomeration of nano-nickel oxide particles, reducing the uniformity of the generated nickel oxide film; (3) the pH sensitivity is low, which limits the controllability of the nickel oxide nucleation process. Summary of the invention

[0005] The present invention effectively solves the above technical problems faced by the existing chemical bath deposition technology for preparing nickel oxide thin films by disclosing a method for preparing nickel oxide thin films and its products and applications.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] In a first aspect, the present invention provides a method for preparing a nickel oxide thin film. The method for preparing a nickel oxide thin film of the present invention comprises:

[0008] providing a homogeneous aqueous solution containing a nickel source compound and a basic amino acid;

[0009] The homogeneous aqueous solution is brought into contact with the surface of the substrate to be coated and a chemical bath deposition reaction occurs, so that a nickel hydroxide film layer is formed in situ on the surface to be coated;

[0010] Annealing the nickel hydroxide film layer to obtain a nickel oxide film;

[0011] Wherein, the nickel source compound is selected from at least one of nickel sulfate, nickel nitrate, nickel chloride, nickel carbonate, and nickel acetylacetonate; and the basic amino acid is selected from at least one of histidine, arginine, and lysine.

[0012] According to the preparation method disclosed in the present invention, the temperature of the chemical bath deposition reaction is 50-80° C. and the time is 60-180 min.

[0013] According to the preparation method disclosed in the present invention, the molar concentration of the nickel source compound is 0.001~0.5 mol / L, and the molar ratio of the nickel source compound to the basic amino acid is (1.5~2.5):1.

[0014] According to the preparation method disclosed in the present invention, the temperature of the annealing treatment is 270-360° C. and the time is 60-180 min.

[0015] According to the preparation method disclosed in the present invention, the substrate is one of a FTO substrate and an ITO substrate.

[0016] In a second aspect, the present invention further provides a nickel oxide film prepared by the preparation method of the present invention, wherein the thickness of the nickel oxide film is 10-20 nm.

[0017] In a third aspect, the present invention also provides an application of a nickel oxide thin film prepared by the preparation method of the present invention in a hole transport layer of a perovskite solar cell.

[0018] In a fourth aspect, the present invention further provides a perovskite solar cell, whose structure comprises a substrate and a hole transport layer, a perovskite active layer, an interface passivation layer, an electron transport layer and a metal electrode sequentially arranged on the substrate, wherein the hole transport layer comprises a nickel oxide thin film produced by the preparation method of the present invention.

[0019] Compared with the prior art, the advantages or beneficial effects of the embodiments of the present invention include at least:

[0020] The present invention introduces alkaline amino acids into a nickel source chemical bath aqueous solution for chemical bath deposition to obtain a nickel hydroxide film layer, and then anneals at high temperature to convert the nickel hydroxide film layer into a uniform, dense, and crystalline nickel oxide film. Specifically, the alkaline amino acid can form a multi-dentate coordination with nickel ions with moderate strength, effectively and reasonably adjust the nucleation rate of nickel hydroxide, make the generated nickel hydroxide nanoparticles more uniform and fine, and the alkaline amino acid can also prevent the agglomeration of the generated nanoparticles through the steric hindrance effect, effectively improve the dispersion effect of the nanoparticles, thereby synergistically optimizing the deposition behavior of the nickel hydroxide nanoparticles through the above two aspects, and achieving the preparation of a uniform, dense, and crystalline nickel oxide film. In addition, the coordination ability of the alkaline amino acid has pH responsiveness, so that the formation and decomposition of the complex can be controlled by adjusting the pH value of the solution, and it is expected to achieve precise regulation of the nucleation process of nickel hydroxide. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 NiO obtained from the embodiments and comparative examples provided by the present invention x SEM image of the hole transport layer substrate;

[0023] Figure 2 NiO obtained from the embodiments and comparative examples provided by the present invention x XRD spectrum of the hole transport layer substrate;

[0024] Figure 3 A schematic diagram of the structure of a perovskite solar cell device prepared according to an embodiment of the present invention;

[0025] Figure 4 The current-voltage characteristic curve of the perovskite solar cell device manufactured in each example provided by the present invention;

[0026] Figure 5 The photoelectric conversion efficiency distribution diagram of the perovskite solar cell device manufactured in each example provided by the present invention;

[0027] Figure 6 The stability test curve of the perovskite solar cell device manufactured in each example provided by the present invention;

[0028] Figure 7 The figure is a relationship diagram showing the influence of the molar ratio of the nickel source to lysine provided by the present invention on the performance. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] In the following description of this specification, the term "and / or" is used to describe the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, B exists alone, and A and B exist at the same time. A and B can be singular or plural.

[0031] In the following description of this specification, the term "at least one" refers to one or more; "plurality" refers to two or more. "At least one of the following" or similar descriptions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one of A, B or C", or "at least one of A, B and C" all mean one of A, B, C, or A+B, or A+C, or B+C, or A+B+C, where A, B, C can be single or multiple, respectively.

[0032] In the following description of this specification, the order of serial numbers does not mean the order of execution. Some or all of the steps can be executed in parallel or one after the other. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0033] In the following description of this specification, the numerical range is understood to also specifically disclose each intermediate value between the upper and lower limits of the range. Each smaller range between any stated value or intermediate value in the stated range and any other stated value or intermediate value in the stated range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the range.

[0034] Unless otherwise specified, the technical / scientific terms used in this specification have the same meanings as those commonly understood by those skilled in the art. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to the present invention may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the incorporated documents. In the event of a conflict with any incorporated document, the content of the present invention shall prevail.

[0035] In a first aspect, the present invention provides a method for preparing a nickel oxide thin film, the steps of which include:

[0036] providing a homogeneous aqueous solution containing a nickel source compound and a basic amino acid;

[0037] The homogeneous aqueous solution is brought into contact with the surface of the substrate to be coated and a chemical bath deposition reaction occurs, so that a nickel hydroxide film layer is formed in situ on the surface to be coated;

[0038] Annealing the nickel hydroxide film layer to obtain a nickel oxide film;

[0039] The nickel source compound is selected from at least one of nickel sulfate, nickel nitrate, nickel chloride, nickel carbonate and nickel acetylacetonate; and the basic amino acid is selected from at least one of histidine, arginine and lysine.

[0040] The present invention provides a technical strategy of introducing the above alkaline amino acid into a nickel source chemical bath aqueous solution for chemical bath deposition to obtain a nickel hydroxide film layer, and then subjecting the nickel hydroxide film layer to high temperature annealing to convert the nickel hydroxide film layer into a nickel oxide film. Among them, the basic amino acids selected in the present invention can embody at least the following advantages compared with the ligands such as ethanolamine and ammonia water commonly used in the prior art: (1) basic amino acids can form a moderately strong multidentate coordination with nickel ions, thereby providing uniform and efficient nickel ion release during the nucleation process, achieving effective regulation of the nucleation rate of nickel hydroxide, and making the generated nickel hydroxide nanoparticles more uniform and fine and having good crystallinity; (2) the unique side chain structure of basic amino acids can provide a suitable steric hindrance effect, thereby preventing the agglomeration of the generated nanoparticles and ensuring the close arrangement of the nanoparticles through the steric hindrance effect, effectively improving the dispersion effect of the nanoparticles, and synergistically optimizing the distribution and arrangement behavior of the nickel hydroxide nanoparticles, achieving the preparation of a uniform, dense and crystalline nickel oxide film; (3) basic amino acids have unique pH responsiveness, so that their coordination behavior with nickel ions has pH responsiveness, and the formation and decomposition of the complex can be accurately controlled by adjusting the pH value of the solution, effectively achieving precise regulation of the nucleation process of nickel hydroxide.

[0041] It should be noted that the basic amino acid of the present invention is preferably lysine. Among them, the present invention selects histidine, arginine and / or lysine, firstly, by optimizing the coordination strength of the nickel-containing complex to achieve the effect of regulating the nucleation rate of nickel hydroxide, ensuring the generation of nickel hydroxide nanoparticles with small size and good uniformity; secondly, providing appropriate steric hindrance to enhance the dispersion effect of nanoparticles, thereby achieving environmentally friendly preparation of uniform, dense and crystallinity nickel oxide film. Among them, the side chain of lysine is short and linear, which can ensure the dense distribution of nanoparticles while providing appropriate steric hindrance effect to prevent the agglomeration of nanoparticles, so that the prepared nickel oxide film has higher density.

[0042] According to the exemplary scheme of the present disclosure, the temperature of the chemical bath deposition reaction of the present invention is 50-80°C, which can be 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C or any one thereof; the time is 60-180 min, which can be 60 min, 90 min, 120 min, 150 min, 180 min or any one thereof. Among them, the present invention can effectively optimize the deposition rate, crystallinity and thickness by selecting the above chemical bath deposition parameters, so that the prepared nickel oxide film particles are uniform and have good crystallinity.

[0043] According to the exemplary scheme of the present disclosure, the molar concentration of the nickel source compound of the present invention is preferably 0.001-0.5 mol / L, and the molar ratio of the nickel source compound to the basic amino acid is preferably (1.5-2.5):1. In a possible specific example, the nickel source compound is 0.075 mol / L and the basic amino acid is 0.0375 mol / L. Among them, the present invention can optimize the release rate of nickel ions by selecting the above-mentioned material ratio, ensure the smooth deposition process, and make the prepared nickel oxide film particles uniform and have good crystallinity.

[0044] According to the example scheme of the present disclosure, the temperature of the annealing treatment of the present invention is preferably 270-360°C, which can be 270°C, 280°C, 290°C, 300°C, 320°C, 350°C, 360°C or any one thereof; the annealing time is 60-180min, which can be 60 min, 90 min, 120 min, 150 min, 180 min or any one thereof. Among them, the present invention can ensure that nickel hydroxide is completely converted into nickel oxide by selecting the above annealing parameters, thereby improving the purity quality of nickel oxide.

[0045] According to the exemplary embodiment of the present disclosure, the substrate of the present invention is preferably one of a FTO substrate and an ITO substrate. The FTO substrate and the ITO substrate are both understood according to the general meaning in the art, for example, the FTO substrate is fluorine-doped tin oxide, which can be purchased commercially.

[0046] In a second aspect, the present invention further discloses a nickel oxide film prepared by the preparation method of the present invention, wherein the thickness of the nickel oxide film is 10-20 nm.

[0047] In the third aspect, the present invention also discloses an application of a nickel oxide film prepared by the preparation method of the present invention. Specifically, the nickel oxide film of the present invention is used for the hole transport layer of a perovskite solar cell. Among them, since the preparation method of the present invention can optimize the nucleation performance and dispersion effect of the prepared nickel oxide film, the nickel oxide film is made more dense and uniform. Therefore, when the nickel oxide film of the invention is used as the hole transport layer in a perovskite solar cell, the conversion efficiency and stability of the battery can be effectively improved.

[0048] In a fourth aspect, the present invention further provides a perovskite solar cell, the structure of which comprises a substrate and a hole transport layer, a perovskite active layer, an interface passivation layer, an electron transport layer and a metal electrode sequentially arranged on the substrate. The hole transport layer is selected as the nickel oxide film of the present invention.

[0049] It should be noted that the present invention has no special restrictions on the remaining functional layer materials and their preparation in the perovskite solar cell, and they can be prepared by functional layer materials and their general preparation strategies known in the art. For example, the substrate is FTO conductive glass, etc.

[0050] The technical solution of the present invention will be further described below in conjunction with specific embodiments.

[0051] Example 1

[0052] This embodiment provides a preparation method of a perovskite solar cell device, and the specific process includes:

[0053] S1-Substrate cleaning: FTO conductive glass ( ) were placed in a clean culture dish and ultrasonically cleaned with deionized water for 25 min (twice); and ethanol for 25 min (twice), and then dried with a nitrogen gun for later use.

[0054] S2-Hole transport layer deposition: The clean FTO substrate was placed horizontally in a homogeneous aqueous solution containing 0.075 mol / L nickel sulfate and 0.0375 mol / L lysine (ammonia was added to adjust the pH of the homogeneous aqueous solution to 8), and the homogeneous aqueous solution was placed in an oven at 80°C for chemical bath deposition for 120 min. After the chemical bath deposition, it was first placed in ultrapure water for 1 min, and then the excess water was blown off with a nitrogen gun, and finally annealed on a hot stage at 285°C for 120 min to obtain NiO x hole transport layer substrate;

[0055] Take 50 μL of 0.5 mg / mL Me-4PACz solution dissolved in ethanol and drop it on the NiO xThe hole transport layer substrate was spin-coated to form a film. The spin coating procedure was: acceleration 4500 rpm / s, accelerated to 4500 rpm and spin-coated for 30 s. After the program stopped, the obtained wet film was placed on a 100 °C hot plate for heating and annealing for 10 min, and cooled to prepare a hole transport layer.

[0056] S3-Perovskite active-passivation layer preparation: Take 40 μL of the prepared 1.5 M Cs 0.1 FA 0.9 PbI3 perovskite precursor solution (PbI2 excess 8%, and 15% MACl added as an additive). It was added dropwise on the hole transport layer and spin-coated into a film. The spin-coating procedure was: acceleration 1000 rpm / s, accelerated to 5000 rpm for 35 s, 180 μL of chlorobenzene was added as an anti-solvent in the 7th second before the program, and after the program was stopped, the resulting wet film was placed on a 105 ℃ hot stage for heating and annealing for 20 min, cooled, and prepared into a perovskite active layer. 100 μL of 1 mg / ml phenylethylamine iodine isopropanol solution was added dropwise on the perovskite active layer and spin-coated into a film. The spin-coating procedure was: acceleration 5000 rpm / s, accelerated to 5000 rpm for 30 s, and after the program was stopped, the resulting wet film was placed on a 100 ℃ hot stage for heating and annealing for 5 min, cooled, and prepared into a perovskite active-passivation layer.

[0057] S4-Electron transport layer preparation: 30nm C was vacuum-deposited at a vacuum rate of 0.2 Å / s. 60 and 8 nm BCP on the 100 nm interface passivation layer to prepare the electron transport layer.

[0058] S5-Metal Electrode Preparation: Under a vacuum degree of 100 nm, a silver electrode with a thickness of 100 nm was vacuum evaporated on the electron transport layer at a speed of 0.3 Å / s to obtain a perovskite solar cell device.

[0059] Example 2

[0060] This embodiment provides a preparation method of a perovskite solar cell device, and the specific process includes:

[0061] S1-Substrate cleaning: FTO conductive glass ( ) were placed in a clean culture dish and ultrasonically cleaned with deionized water for 25 min (twice); and ethanol for 25 min (twice), and then dried with a nitrogen gun for later use.

[0062] S2-Hole transport layer deposition: The clean FTO substrate was placed horizontally in a homogeneous aqueous solution containing 0.075 mol / L nickel sulfate and 0.0375 mol / L arginine (ammonia was added to adjust the pH of the homogeneous aqueous solution to 8), and the homogeneous aqueous solution was placed in an oven at 80°C for chemical bath deposition for 120 min. After the chemical bath deposition, it was first placed in ultrapure water for 1 min, and then the excess water was blown off with a nitrogen gun, and finally annealed on a hot stage at 285°C for 120 min to obtain NiO x hole transport layer substrate;

[0063] Take 50 μL of 0.5 mg / mL Me-4PACz solution dissolved in ethanol and drop it on the NiO x The hole transport layer substrate was spin-coated to form a film. The spin coating procedure was: acceleration 4500 rpm / s, accelerated to 4500 rpm and spin-coated for 30 s. After the program stopped, the obtained wet film was placed on a 100 °C hot plate for heating and annealing for 10 min, and cooled to prepare a hole transport layer.

[0064] S3-Perovskite active-passivation layer preparation: Take 40 μL of the prepared 1.5 M Cs 0.1 FA 0.9 PbI3 perovskite precursor solution (PbI2 excess 8%, and 15% MACl added as an additive). It was added dropwise on the hole transport layer and spin-coated into a film. The spin-coating procedure was: acceleration 1000 rpm / s, accelerated to 5000 rpm for 35 s, 180 μL of chlorobenzene was added as an anti-solvent in the 7th second before the program, and after the program was stopped, the resulting wet film was placed on a 105 ℃ hot stage for heating and annealing for 20 min, cooled, and prepared into a perovskite active layer. 100 μL of 1 mg / ml phenylethylamine iodine isopropanol solution was added dropwise on the perovskite active layer and spin-coated into a film. The spin-coating procedure was: acceleration 5000 rpm / s, accelerated to 5000 rpm for 30 s, and after the program was stopped, the resulting wet film was placed on a 100 ℃ hot stage for heating and annealing for 5 min, cooled, and prepared into a perovskite active-passivation layer.

[0065] S4-Electron transport layer preparation: 30nm C was vacuum-deposited at a vacuum rate of 0.2 Å / s. 60 and 8 nm BCP on the 100 nm interface passivation layer to prepare the electron transport layer.

[0066] S5-Metal Electrode Preparation: Under a vacuum degree of 100 nm, a silver electrode with a thickness of 100 nm was vacuum evaporated on the electron transport layer at a speed of 0.3 Å / s to obtain a perovskite solar cell device.

[0067] Example 3

[0068] This embodiment provides a preparation method of a perovskite solar cell device, and the specific process includes:

[0069] S1-Substrate cleaning: FTO conductive glass ( ) were placed in a clean culture dish and ultrasonically cleaned with deionized water for 25 min (twice); and ethanol for 25 min (twice), and then dried with a nitrogen gun for later use.

[0070] S2-Hole transport layer deposition: The clean FTO substrate was placed horizontally in a homogeneous aqueous solution containing 0.075 mol / L nickel sulfate and 0.0375 mol / L histidine (ammonia was added to adjust the pH of the homogeneous aqueous solution to 8), and the homogeneous aqueous solution was placed in an oven at 80 °C for chemical bath deposition for 120 min. After the chemical bath deposition, it was first placed in ultrapure water for 1 min, and then the excess water was blown off with a nitrogen gun, and finally annealed on a hot stage at 285 °C for 120 min to obtain NiO x hole transport layer substrate;

[0071] Take 50 μL of 0.5 mg / mL Me-4PACz solution dissolved in ethanol and drop it on the NiO x The hole transport layer substrate was spin-coated to form a film. The spin coating procedure was: acceleration 4500 rpm / s, accelerated to 4500 rpm and spin-coated for 30 s. After the program stopped, the obtained wet film was placed on a 100 °C hot plate for heating and annealing for 10 min, and cooled to prepare a hole transport layer.

[0072] S3-Perovskite active-passivation layer preparation: Take 40 μL of the prepared 1.5 M Cs 0.1 FA 0.9 PbI3 perovskite precursor solution (PbI2 excess 8%, and 15% MACl added as an additive). It was added dropwise on the hole transport layer and spin-coated into a film. The spin-coating procedure was: acceleration 1000 rpm / s, accelerated to 5000 rpm for 35 s, 180 μL of chlorobenzene was added as an anti-solvent in the 7th second before the program, and after the program was stopped, the resulting wet film was placed on a 105 ℃ hot stage for heating and annealing for 20 min, cooled, and prepared into a perovskite active layer. 100 μL of 1 mg / ml phenylethylamine iodine isopropanol solution was added dropwise on the perovskite active layer and spin-coated into a film. The spin-coating procedure was: acceleration 5000 rpm / s, accelerated to 5000 rpm for 30 s, and after the program was stopped, the resulting wet film was placed on a 100 ℃ hot stage for heating and annealing for 5 min, cooled, and prepared into a perovskite active-passivation layer.

[0073] S4-Electron transport layer preparation: 30nm C was vacuum-deposited at a vacuum rate of 0.2 Å / s. 60 and 8 nm BCP on the 100 nm interface passivation layer to prepare the electron transport layer.

[0074] S5-Metal Electrode Preparation: Under a vacuum degree of 100 nm, a silver electrode with a thickness of 100 nm was vacuum evaporated on the electron transport layer at a speed of 0.3 Å / s to obtain a perovskite solar cell device.

[0075] In order to illustrate the NiO prepared in the present embodiment x The present invention provides comparative examples 1-2 for the structural performance of the hole transport layer substrate, and the present invention illustrates them in conjunction with the following test results.

[0076] Comparative Example 1

[0077] The difference between this comparative example and Example 1 is that only lysine is replaced by ethanolamine, and ammonia water is added to adjust the pH of the homogeneous aqueous solution to 8, and the rest are the same.

[0078] Comparative Example 2

[0079] The difference between this comparative example and Example 1 is that only lysine is replaced by ammonium chloride, and ammonia water is added to adjust the pH of the homogeneous aqueous solution to 8, and the rest are the same.

[0080] Test Example 1

[0081] For the sake of distinction, the NiO prepared in Example 1 x The hole transport layer substrate is abbreviated as NiO x -Lys, the corresponding perovskite solar cell is abbreviated as PSCs-NiO x -Lys; NiO prepared in Example 2 x The hole transport layer substrate is abbreviated as NiO x -Arg, the corresponding perovskite solar cell is abbreviated as PSCs-NiO x -Arg; NiO prepared in Example 3 x The hole transport layer substrate is abbreviated as NiO x -His, the corresponding perovskite solar cells are abbreviated as PSCs-NiO x -His; NiO prepared in Comparative Example 1 x The hole transport layer substrate is abbreviated as NiO x -ETA, the corresponding perovskite solar cells are abbreviated as PSCs-NiO x -ETA; NiO prepared in Comparative Example 2 x The hole transport layer substrate is abbreviated as NiO x-NH4 + The corresponding perovskite solar cell is abbreviated as PSCs-NiO x -NH4 + .

[0082] 1. SEM characterization.

[0083] The NiO prepared in the examples and comparative examples x The hole transport layer substrate was characterized by scanning electron microscopy (SEM), and the results were Figure 1 As shown. Among them, Figure 1 NiO obtained in the examples and comparative examples x SEM image of the hole transport layer substrate.

[0084] according to Figure 1 It can be seen that when lysine, arginine and histidine are introduced in the above examples, the density and uniformity of the prepared nickel oxide film are better than those of Comparative Examples 1 and 2. In particular, the introduction of lysine can obtain a nickel oxide film with better uniformity, density and conformal coverage, which may be because the side chain of lysine is short and linear, providing steric hindrance without greatly affecting its density.

[0085] 2. XRD characterization

[0086] The NiO obtained in the examples and comparative examples x The hole transport layer substrate was subjected to X-ray diffraction (XRD), and the results were Figure 2 As shown. Among them, Figure 2 NiO obtained in the examples and comparative examples x XRD spectrum of the hole transport layer substrate.

[0087] according to Figure 2 It can be seen that when lysine, arginine and histidine are introduced, the density and uniformity of the obtained nickel oxide film are better than those of Comparative Examples 1 and 2. In particular, when lysine is introduced, a nickel oxide film with a smaller size, more uniform particle size and conformal coverage is obtained, and the nickel oxide film is more fully exposed to oxygen during the annealing process, so the obtained nickel oxide film has better crystallinity.

[0088] 3. Photoelectric performance characterization

[0089] The perforation area is 0.059 cm 2 A 0.1 mm thick metal sheet was used as a shading template, and the photoelectric performance of the perovskite solar cell device manufactured in the embodiment of the present invention and the comparative example was tested under the AM 1.5 G light provided by a 3A-level solar simulator. The results were as follows: Figure 3-5 As shown. Among them, Figure 3 A schematic diagram of the structure of a perovskite solar cell device prepared in the embodiment; Figure 4The current-voltage characteristic curve of the perovskite solar cell device manufactured in each example; Figure 5 The photoelectric conversion efficiency distribution diagram of the perovskite solar cell devices manufactured in each example.

[0090] according to Figure 3 It can be seen that the thickness of the nickel oxide film prepared by chemical bath deposition is 10~20 nm.

[0091] According to Figure 4, the performance of the devices manufactured by the nickel oxide thin films introduced with basic amino acids in Examples 1 to 3 is generally higher than that of Comparative Examples 1 and 2. Among them, the photoelectric conversion efficiency of Example 1 is 25.55%; the photoelectric conversion efficiency of Example 2 is 25.12%; and the photoelectric conversion efficiency of Example 3 is 25.18%.

[0092] according to Figure 5 It can be seen that statistical analysis of 6 independently prepared samples in the same batch shows that the average photoelectric conversion efficiency of the device in Example 1 is the highest at 25.37%; the average photoelectric conversion efficiency of the device in Example 2 is 25.09%; the average photoelectric conversion efficiency of the device in Example 3 is 25.07%; the average photoelectric conversion efficiency of the device in Comparative Example 1 is 24.42%; the average photoelectric conversion efficiency of the device in Comparative Example 2 is 22.29%, indicating that the photoelectric conversion efficiency and repeatability of the device prepared by the nickel oxide film obtained by using basic amino acids, especially lysine as a ligand are higher than those of Comparative Examples 1 and 2. The reason may be that the introduction of lysine can obtain a nickel oxide film with more uniform particle size, denser morphology, and better crystallinity, and these advantages are more conducive to the subsequent deposition of the perovskite layer, thereby obtaining a device with higher photoelectric conversion efficiency.

[0093] 4. Stability test

[0094] In the environmental chamber, the accelerated aging test was carried out at 35±5% humidity and 60°C. The results were Figure 6 As shown. Among them, Figure 6 These are stability test curves of the perovskite solar cell devices manufactured in each example.

[0095] according to Figure 6It can be seen that the device prepared by the nickel oxide film obtained by introducing alkaline amino acids can maintain better wet heat stability at a higher photoelectric conversion efficiency than comparative examples 1 and 2. Among them, the nickel oxide film obtained by introducing lysine in Example 1 has the best stability, and its photoelectric conversion efficiency remains at 95.1% of the initial efficiency after 1500 hours of aging test; Example 2, after 1500 hours of aging test, its photoelectric conversion efficiency remains at 93.5% of the initial efficiency; Example 3, after 1500 hours of aging test, its photoelectric conversion efficiency remains at 92.2% of the initial efficiency; Comparative Example 1, after 1500 hours of aging test, its photoelectric conversion efficiency remains at 80.4% of the initial efficiency; Comparative Example 2, after 1500 hours of aging test, its photoelectric conversion efficiency remains at 62.1% of the initial efficiency.

[0096] 5. Effect of the molar ratio of nickel source to basic amino acid on performance

[0097] Keeping other preparation conditions of Example 1 unchanged, nickel sulfate was used as the nickel source and lysine was used as the ligand to explore the effect of the nickel source and the amount of ligand on the photoelectric conversion efficiency. Figure 7 This is a graph showing the effect of the molar ratio of nickel source to lysine on performance.

[0098] according to Figure 7 It can be seen that when the molar ratio of nickel source to lysine is 2.0:1, the maximum photoelectric conversion efficiency is obtained, and the average photoelectric conversion efficiency is 25.35%. When the molar ratio of nickel source to lysine is 1.5:1, 1.75:1, 2.25:1, and 2.5:1, the average photoelectric conversion efficiency is 24.77%, 24.95%, 24.96%, and 24.81%, respectively.

[0099] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0100] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

Claims

1. A method for preparing a nickel oxide thin film, comprising: providing a homogeneous aqueous solution containing a nickel source compound and a basic amino acid; The homogeneous aqueous solution is brought into contact with the surface of the substrate to be coated and a chemical bath deposition reaction occurs, so that a nickel hydroxide film layer is formed in situ on the surface to be coated; Annealing the nickel hydroxide film layer to obtain a nickel oxide film; in, The nickel source compound is selected from at least one of nickel sulfate, nickel nitrate, nickel chloride, nickel carbonate, and nickel acetylacetonate; and the basic amino acid is selected from at least one of histidine, arginine, and lysine.

2. The preparation method according to claim 1, characterized in that: The temperature of the chemical bath deposition reaction is 50-80° C. and the time is 60-180 min.

3. The preparation method according to claim 1, characterized in that: The molar concentration of the nickel source compound is 0.001-0.5 mol / L, and the molar ratio of the nickel source compound to the basic amino acid is (1.5-2.5):

1.

4. The preparation method according to claim 1, characterized in that: The annealing treatment is performed at a temperature of 270-360°C and for a time of 60-180 min.

5. The preparation method according to claim 1, characterized in that: The substrate is one of a FTO substrate and an ITO substrate.

6. A nickel oxide film, characterized in that: The method comprises preparing the film by the preparation method according to any one of claims 1 to 5, and the thickness thereof is 10 to 20 nm.

7. Application of the nickel oxide thin film prepared by the preparation method according to any one of claims 1 to 5 in a hole transport layer of a perovskite solar cell.

8. A perovskite solar cell comprising a substrate and a hole transport layer, a perovskite active layer, an interface passivation layer, an electron transport layer and a metal electrode sequentially arranged on the substrate, wherein: The hole transport layer comprises a nickel oxide thin film prepared by the preparation method according to any one of claims 1 to 5.

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