A method for one-step efficient preparation of perovskite layer-hole transport layer

Abstract

The application relates to a method for one-step high-efficiency preparation of a perovskite layer-hole transport layer, and the specific steps are as follows: 1) a perovskite precursor solution is prepared, then 1,4-butane sulfolactam and a hole transport material are added into the solution, oscillation is carried out until complete dissolution, and a mixed solution of the perovskite and the hole transport material is obtained; 2) the mixed solution of the perovskite and the hole transport material obtained in the step 1) is coated on a surface-cleaned ITO conductive substrate to obtain a precursor thin film, and then the obtained precursor thin film is subjected to annealing treatment, so that a composite thin film of a lower hole transport layer and an upper perovskite layer is obtained. The preparation method provided by the application can realize one-step deposition to obtain a high-quality perovskite layer / hole layer heterojunction thin film, the conversion efficiency of a p-i-n perovskite solar cell is also improved to a certain extent, the preparation process is simplified, the production cost is reduced, and the method has a positive significance for large-scale preparation of the perovskite solar cell.

Description

Technical Field

[0001] This invention belongs to the field of electrical component technology, specifically relating to a one-step, efficient method for preparing a perovskite layer-hole transport layer. Background Technology

[0002] With the continued growth in global demand for green energy, the scale of solar energy applications has expanded significantly. my country's photovoltaic industry has maintained a strong development momentum, ranking first in the world for 11 consecutive years in terms of annual newly installed capacity. According to statistics from the National Energy Administration, my country's newly installed solar photovoltaic capacity reached 216.88 GW in 2023, setting a new historical record.

[0003] Perovskite solar cells are a type of high-efficiency solar cell with enormous commercial application potential. Typically, to form high-quality pin or nip heterojunctions, three functional layers (hole transport layer, perovskite layer, and electron transport layer) are deposited sequentially in three steps to ensure the density and uniformity of each thin film, thereby achieving good charge transport and reducing voltage loss. To improve production efficiency, methods such as transport layer-less deposition and co-deposition of the transport layer (HTL / ETL) with the perovskite layer have been proposed. However, the quality of perovskite heterojunctions prepared by existing methods still falls short of those produced by layer-by-layer deposition methods, resulting in a corresponding impact on cell efficiency.

[0004] This invention introduces 1,4-butanesulfonamide into a mixed solution of perovskite precursor and hole transport material, and obtains a titanium oxide layer and a hole transport layer in a single deposition, resulting in a high-quality perovskite heterojunction. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to address the shortcomings of the existing technology by providing a one-step efficient method for preparing a perovskite layer-hole transport layer. This method can simultaneously deposit a dense perovskite layer and a hole transport layer in one step, which can effectively reduce the preparation cost and improve the production efficiency.

[0006] This invention provides a one-step, efficient method for preparing a perovskite layer-hole transport layer, the specific steps of which are as follows:

[0007] 1) Prepare a perovskite precursor solution, then add 1,4-butanesulfonamide and hole transport material to the solution, and shake until completely dissolved to obtain a mixed solution of perovskite and hole transport material;

[0008] 2) The mixed solution of perovskite and hole transport material obtained in step 1) is coated on a clean ITO conductive substrate to obtain a precursor film. The precursor film is then annealed to obtain a composite film with a lower hole transport layer and an upper perovskite layer (perovskite layer / hole transport layer heterojunction).

[0009] According to the above scheme, the preparation method of the perovskite precursor solution in step 1) is as follows: weigh the corresponding FAPbI3 and MA x FA 1-x Pb(I y Br 1-y )3 or Cs x FA 1-x Pb(I y Br 1-y The raw material )3 is mixed with methylamine chloride (MACl) at a molar amount of 5-40% of PbI2 in the raw material and dissolved in a solvent to obtain a perovskite precursor solution with a concentration of 1-2M.

[0010] According to the above scheme, the solvent is a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) in a volume ratio of 4 to 7:1, or a mixed solvent of 2-methoxyethanol (2-ME) and 1,3-dimethyl-2-imidazolinone (DMI) in a volume ratio of 4 to 7:1.

[0011] According to the above scheme, the hole transport material in step 1) is one of (2-(9H-carbazole-9-yl)ethyl)phosphonic acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid, and [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid.

[0012] According to the above scheme, in step 1), the concentration of 1,4-butanesulfonamide in the mixed solution of perovskite and hole transport material is 0.05-0.2 M (mol / L), and the concentration of hole transport material is 0.001-0.01 M.

[0013] According to the above scheme, step 2) involves coating the mixed solution of perovskite and hole transport material onto a clean ITO conductive substrate using one of the following methods: spin coating, blade coating, or slot coating. When using spin coating, the spin coating speed is 4000–5000 rpm, and the spin coating time is 40–50 seconds.

[0014] According to the above scheme, the annealing process conditions for step 2) are: annealing temperature of 120-130℃ and annealing time of 20-40 minutes.

[0015] The present invention also includes the application of the above-described method for efficiently preparing a perovskite layer-hole transport layer in the fabrication of perovskite solar cells.

[0016] The present invention also includes a perovskite layer-hole transport layer prepared according to the above method, wherein the band gap of the perovskite layer is 1.55 to 1.77 eV, the thickness of the perovskite layer is 500 to 900 nm, and the thickness of the hole layer is 1 to 3 nm.

[0017] Furthermore, the present invention also includes a perovskite solar cell containing the above-mentioned perovskite layer-hole transport layer, which includes, from bottom to top, an ITO conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer, a buffer layer, and a top electrode.

[0018] This invention also includes a method for preparing the above-mentioned perovskite solar cell, the specific steps of which are as follows:

[0019] 1) Prepare a perovskite precursor solution, then add 1,4-butanesulfonamide and hole transport material to the solution, and shake until completely dissolved to obtain a mixed solution of perovskite and hole transport material;

[0020] 2) The mixed solution of perovskite and hole transport material obtained in step 1) is coated on a clean ITO conductive substrate to obtain a precursor film. The precursor film is then annealed to obtain a composite film with a lower hole transport layer and an upper perovskite layer.

[0021] 3) An electron transport layer, a buffer layer, and a top electrode are sequentially deposited on the surface of the composite thin film obtained in step 2) consisting of the lower hole transport layer and the upper perovskite layer to obtain a perovskite solar cell (pin type).

[0022] According to the above scheme, the electron transport layer in step 3) is C 60 Alternatively, tin oxide with a thickness of 20–30 nm, a buffer layer of copper bath with a thickness of 10–20 nm, and a top electrode of silver or copper with a thickness of 80–100 nm.

[0023] In the process of preparing the perovskite layer-hole transport layer, this invention discovered that adding an appropriate amount of 1,4-butanesulfonamide to the system and then annealing it can enable the hole transport material to be uniformly and densely deposited at the bottom of the film, while a dense perovskite layer is formed at the top of the film, thus obtaining a two-layer functional material of perovskite layer-hole transport layer in one step.

[0024] The beneficial effects of this invention are as follows: the preparation method provided by this invention can achieve one-step deposition of high-quality perovskite layer / hole layer heterojunction thin films, and the conversion efficiency of pin perovskite solar cells is also improved to a certain extent. It simplifies the preparation process, reduces production costs, and has positive significance for the large-scale preparation of perovskite solar cells. Attached Figure Description

[0025] Figure 1 This is a flowchart illustrating the preparation of perovskite layer / hole transport layer heterojunctions in Embodiment 1 and Comparative Example 1 of the present invention;

[0026] Figure 2Cross-section and lower interface scanning electron microscope images of the perovskite layer / hole transport layer heterojunctions prepared in Example 1 and Comparative Example 1;

[0027] Figure 3 The SEM image of the hole transport layer surface obtained in step 4) of Comparative Example 2;

[0028] Figure 4 The JV curves are for the pin perovskite solar cells obtained in Examples 1, 2, 1, and 2. Detailed Implementation

[0029] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below using embodiments and in conjunction with the accompanying drawings.

[0030] Example 1

[0031] A method for efficient one-step preparation of a perovskite layer-hole transport layer, comprising the following steps:

[0032] 1) Treatment of ITO conductive substrate (2.5cm×2.5cm): The substrate was ultrasonically cleaned with pure water, ethanol and isopropanol for 10 minutes in sequence, and then treated with ultraviolet ozone cleaning machine for 20 minutes.

[0033] 2) Prepare the perovskite solution by weighing 1 mmol FAPbI3 and 0.2 mmol methylamine chloride (MACl), dissolving them in 1 mL of a binary solvent of 2-methoxyethanol and 1,3-dimethyl-2-imidazolinone (v:v = 7:1), and then adding 0.1 mmol

[0034] 1,4-Butanesulfonamide and 0.001 mmol [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphoric acid were shaken until completely dissolved to obtain a mixed solution of perovskite and hole transport material;

[0035] 3) Spin-coat the mixed solution of perovskite and hole transport material obtained in step 2) onto an ITO conductive substrate at a spin speed of 5000 rpm for 45 seconds. Then anneal at 120°C for 30 minutes to obtain a perovskite layer / hole transport layer heterojunction, wherein the thickness of the perovskite layer is about 800 nm and the band gap is about 1.52 eV, and the thickness of the hole transport layer is about 2 nm.

[0036] The process flow and product structure diagram for preparing the perovskite layer / hole transport layer heterojunction in this embodiment are shown below. Figure 1 As shown in Figure A, by adding 1,4-butanesulfonamide to the system, high-quality perovskite and hole layer films can be obtained simultaneously in a single spin-coating step. The SEM morphology of the heterojunction cross-section obtained in this example is shown in Figure A. Figure 2As shown in Figure A, hole transport molecules aggregate between the perovskite and ITO conductive substrates, forming a hole transport layer film approximately 2 nm thick. The upper surface of the heterojunction was bonded to another piece of glass using UV-curable adhesive. The heterojunction film was then peeled off from the original substrate, exposing the lower surface. Its SEM morphology is shown in Figure A. Figure 2 As shown in Figure B, the hole layer is uniform and dense, and it grows conformally on the ITO substrate. Its surface completely replicates the morphology of ITO and is well integrated with the perovskite layer.

[0037] 30 nm C layers were sequentially deposited on the surface of the above perovskite film. 60 A pin-structured perovskite solar cell was obtained by using an 8nm copper bath electrode and a 100nm silver electrode. The JV curve of the obtained pin-structured perovskite solar cell is shown in the figure. Figure 4 As shown, the reverse scanning efficiency reached 25.11%, and the forward scanning efficiency reached 24.90%.

[0038] Comparative Example 1

[0039] A method for preparing a perovskite layer-hole transport layer, which differs from Example 1 in that 1,4-butanesulfonamide is not added, while the remaining steps are the same as in Example 1.

[0040] The process and product structure diagram for the comparative preparation of perovskite layer / hole transport layer heterojunctions are shown below. Figure 1 As shown in Figure B, using this comparative method, pores are easily formed between the perovskite layer and the substrate, resulting in an uneven and non-dense void layer.

[0041] The SEM images of the heterojunction cross section and the peeled lower surface (peeling method is the same as in Example 1) obtained in this comparative example are shown below. Figure 2 As shown in C and D, it can be seen that hole-transporting molecules have difficulty accumulating between the perovskite and ITO layers. The cross-sectional morphology shows many voids at the cross-sectional junction. The lower interface (is...) Figure 2 The morphology of D) shows that hole transport molecules cannot completely cover the perovskite layer, and some perovskite is exposed, which is not conducive to the extraction and transport of charge carriers.

[0042] In this comparative example, 30 nm of C is sequentially deposited on the surface of the perovskite thin film. 60 A pin-structured perovskite solar cell was obtained by using an 8nm copper bath electrode and a 100nm silver electrode. The JV curve of the obtained pin-structured perovskite solar cell is shown in the figure. Figure 4 As shown, its reverse scanning efficiency is only 21.81%, and its forward scanning efficiency is 21.50%, which is far lower than that of Example 1.

[0043] Comparative Example 2

[0044] A method for preparing a perovskite layer-hole transport layer layer layer by layer, the specific steps of which are as follows:

[0045] 1) Treatment of ITO conductive substrate (2.5cm×2.5cm): The substrate was ultrasonically cleaned in pure water, ethanol and isopropanol for 10 minutes in sequence, and then treated with ultraviolet ozone cleaning machine for 20 minutes.

[0046] 2) Prepare the hole material solution by dissolving 0.001 mmol of [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphoric acid in 1 mL of ethanol to obtain the hole material solution;

[0047] 3) Prepare perovskite solution: Weigh 1 mmol FAPbI3 and 0.2 mmol methylamine chloride, dissolve them in 1 mL of 2-methoxyethanol and 1,3-dimethyl-2-imidazolinone binary solvent (v:v = 7:1), shake until completely dissolved, and obtain perovskite solution;

[0048] 4) Spin-coat the hole material solution obtained in step 2) onto the ITO conductive substrate at a spin speed of 4000 rpm for 20 seconds, and anneal at 100°C for 10 minutes. The thickness of the resulting hole transport layer is approximately 2 nm.

[0049] 5) Spin-coat the perovskite solution obtained in step 3) onto the hole transport layer obtained in step 4) at a spin speed of 5000 rpm for 45 seconds. Then anneal at 120°C for 30 minutes to obtain a perovskite layer / hole transport layer heterojunction, wherein the thickness of the perovskite layer is about 800 nm and the band gap is about 1.52 eV.

[0050] The SEM morphology of the hole transport layer surface obtained in step 4) of this comparative example is as follows: Figure 3 As shown, during the layer-by-layer deposition, the [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphate molecules aggregated, resulting in numerous protrusions on the film surface. This is detrimental to interfacial bonding and carrier transport at the interface. In this comparative example, 30 nm thick C layers were sequentially deposited on the surface of the perovskite film. 60 A pin-structured perovskite solar cell was obtained by using an 8nm copper bath electrode and a 100nm silver electrode. The JV curve of the obtained pin-structured perovskite solar cell is shown in the figure. Figure 4 As shown, its reverse scanning efficiency is 24.22% and its forward scanning efficiency is 23.65%, which is lower than that of Example 1.

[0051] Example 2

[0052] A method for preparing a perovskite layer-hole transport layer in one step is different from that in Example 1 in step 3) of coating the mixed solution of perovskite and hole transport material onto an ITO conductive substrate. Instead, a doctor blade coating and printing method is used, with a distance of 150 μm between the blade and the substrate, an air knife pressure of 0.4 MPa, and a printing speed of 7 mm / s. The remaining steps are the same as in Example 1. The thickness of the resulting perovskite layer is approximately 600 nm, and the thickness of the hole transport layer is approximately 2 nm.

[0053] In this comparative example, 30 nm of C is sequentially deposited on the surface of the perovskite thin film. 60 A pin-structured perovskite solar cell was obtained by using an 8nm copper bath electrode and a 100nm silver electrode. The JV curve of the pin-structured perovskite solar cell obtained in this comparative example is shown below. Figure 4 As shown, the reverse scan efficiency is 24.33%, and the forward scan efficiency is 23.82%, with battery performance similar to that of Example 1. This confirms that blade coating can still form a high-quality perovskite / hole transport layer heterojunction.

Claims

1. A method for one-step, efficient preparation of a perovskite layer-hole transport layer, characterized in that, The specific steps are as follows: 1) Prepare a perovskite precursor solution, then add 1,4-butanesulfonamide and hole transport material to the solution, and shake until completely dissolved to obtain a mixed solution of perovskite and hole transport material. The perovskite precursor solution is prepared by weighing the corresponding FAPbI3 and MA... x FA 1-x Pb(I y Br 1-y )3 or Cs x FA 1-x Pb(I y Br 1-y The raw material )3 is mixed with methylamine chloride, which accounts for 5-40% of the molar amount of PbI2 in the raw material, and dissolved in a solvent to obtain a perovskite precursor solution. The concentration of the perovskite precursor solution is 1-2M. The hole transport material is one of (2-(9H-carbazole-9-yl)ethyl)phosphonic acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid, and [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid. 2) The mixed solution of perovskite and hole transport material obtained in step 1) is coated on a clean ITO conductive substrate to obtain a precursor film. The precursor film is then annealed to obtain a composite film with a lower hole transport layer and an upper perovskite layer.

2. The method for one-step efficient preparation of a perovskite layer-hole transport layer according to claim 1, characterized in that, In step 1), the concentration of 1,4-butanesulfonamide in the mixed solution of perovskite and hole transport material is 0.05~0.2M, and the concentration of hole transport material is 0.001~0.01M.

3. The method for one-step efficient preparation of a perovskite layer-hole transport layer according to claim 1, characterized in that, Step 2) The annealing process conditions are: annealing temperature of 120~130℃ and annealing time of 20~40 minutes.

4. The application of the one-step efficient method for preparing a perovskite layer-hole transport layer according to any one of claims 1-3 in the preparation of perovskite solar cells.

5. The perovskite-hole transport layer prepared by the one-step efficient preparation method according to any one of claims 1-3, characterized in that, The perovskite layer has a band gap of 1.55–1.77 eV, a thickness of 500–900 nm, and a hole layer thickness of 1–3 nm.

6. A perovskite solar cell comprising the perovskite layer-hole transport layer as described in claim 5, characterized in that, It comprises, from bottom to top, an ITO conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer, a buffer layer, and a top electrode.

7. A method for preparing a perovskite solar cell according to claim 6, characterized in that, The specific steps are as follows: 1) Prepare a perovskite precursor solution, then add 1,4-butanesulfonamide and hole transport material to the solution, and shake until completely dissolved to obtain a mixed solution of perovskite and hole transport material; 2) The mixed solution of perovskite and hole transport material obtained in step 1) is coated on a clean ITO conductive substrate to obtain a precursor film. The precursor film is then annealed to obtain a composite film with a lower hole transport layer and an upper perovskite layer. 3) An electron transport layer, a buffer layer, and a top electrode are sequentially deposited on the surface of the composite thin film obtained in step 2) consisting of the lower hole transport layer and the upper perovskite layer to obtain a perovskite solar cell.

8. The method for preparing a perovskite solar cell according to claim 7, characterized in that, Step 3) The electron transport layer is C 60 Alternatively, tin oxide with a thickness of 20-30 nm, a buffer layer of copper bath with a thickness of 10-20 nm, and a top electrode of silver or copper with a thickness of 80-100 nm.

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