Integrated passivated perovskite battery based on solution induction and preparation thereof

Abstract

The invention discloses an integrated passivated perovskite battery based on solution induction and preparation thereof. The method comprises the following steps: preparing a perovskite precursor solution by using solvents with different boiling points; meO-4pacz is dropwise added on the FTO substrate, spin coating and annealing treatment are carried out, and a hole transport layer is obtained; a perovskite precursor solution is spin-coated on the surface of the obtained hole transport layer, spin-coating is carried out step by step, an anti-solvent is dropwise added in the spin-coating process, then annealing treatment is carried out, and a perovskite light absorption layer is obtained; dropwise adding a passivating agent on the obtained perovskite light absorption layer, and carrying out spin coating and annealing treatment; repeating once to obtain a passivation layer; and sequentially preparing an electron transport layer and an electrode on the passivation layer to obtain the integrated perovskite solar cell. According to the method, the high-boiling-point small-molecule solvent is added into the perovskite precursor solution, evaporation is performed in the subsequent perovskite layer annealing process, and a channel for the passivator to enter is reserved in the bulk phase in the crystal forming process, so that the effect of integrally passivating the surface and the bulk phase of the perovskite is achieved.

Description

Technical Field

[0001] This invention relates to the field of perovskite battery technology, specifically to a solution-induced integrated passivated perovskite battery and its fabrication. Background Technology

[0002] As a key emerging material in third-generation photovoltaic technology, perovskite solar cells (PSCs) have attracted widespread attention from the global scientific community over the past decade due to their superior photoelectric performance, low cost, and simple fabrication process. The efficiency of traditional single-junction silicon solar cells has gradually approached its theoretical limit, and further improvements face numerous challenges. However, combining wide-bandgap perovskite solar cells with narrow-bandgap silicon or other inorganic semiconductor materials can create multi-junction tandem solar cells. By rationally designing and optimizing the bandgap of each layer, the photoelectric conversion efficiency of solar cells can be significantly improved, breaking through the bottleneck of single-junction cell efficiency.

[0003] However, wide-bandgap perovskite solar cells still face many technical challenges. Due to the need for high bromine content to achieve bandgap widening, the rapid crystallization kinetics of bromides easily lead to crystallization disorder, lattice strain accumulation, and high-density point defects within the film. This further induces phase separation between iodine-rich and bromine-rich regions under illumination or an electric field, exacerbating nonradiative recombination. At the interface level, a large amount of uncoordinated Pb exists at the buried interface and the top surface. 2+ The presence of vacancy defects leads to a significant open-circuit voltage (Voc) deficit, making its actual voltage level far below its theoretical limit (Shockley-Quyese limit). In terms of stability, thermal cycling induces lattice strain accumulation and phase transition degradation, while traditional passivating agents are prone to desorption under photothermal stress, resulting in loss of passivation effectiveness. These degradation mechanisms collectively contribute to the rapid decline in device stability.

[0004] In existing technologies, research on wide-bandgap perovskite solar cells mostly focuses on reducing defects and improving stability through bulk doping, surface passivation, and crystallization kinetics control. For example, adding OCN to the bulk phase... - Pseudohalogen alloying induces (110) preferred orientation, fills halogen vacancies, stabilizes the lattice through hydrogen bond network, and increases the ion migration barrier; selectively inhibits the excessively rapid crystallization of bromine-rich phase and accelerates the delayed crystallization of iodine-rich phase, thereby achieving synchronous crystallization of halogen phase and reducing defect density.

[0005] These methods can improve the efficiency and stability of wide-bandgap perovskite solar cells to some extent, but they also have the following problems: complex operation processes, difficulty in precisely controlling the treatment effect, and low universality. For example, when controlling crystallization kinetics by preferential coordination with PbBr2, the effectiveness of the control is highly dependent on the interaction time window between the additive and the perovskite precursor. In the actual film formation process, many factors will affect the degree of coordination with PbBr2. If the coordination reaction is not fully completed before the critical crystallization node, it may introduce new nucleation inhomogeneities. The efficiency of passivating agents may be highly dependent on specific perovskite components. When transplanted to other wide-bandgap components, the improvement effect may vary significantly. Summary of the Invention

[0006] To address the above technical problems, this invention provides a method for fabricating a solution-induced integrated passivation perovskite solar cell. Building upon the successful fabrication of a perovskite solar cell with high photoelectric conversion efficiency, this invention regulates perovskite crystallization, improving the quality of the thin film and thus producing a wide-bandgap perovskite solar cell with superior photoelectric conversion efficiency and stability. The perovskite solar cell thin film comprises a conductive substrate, a hole transport layer, an electron transport layer, and a perovskite light-absorbing layer sequentially arranged, and is processed by spin coating and annealing. This invention achieves integrated passivation of the perovskite surface and bulk phase by adding a high-boiling-point small-molecule solvent NMP to the perovskite precursor solution and evaporating the NMP during subsequent perovskite layer annealing. This leaves channels in the bulk phase during crystal formation for the passivating agent to enter, thereby achieving integrated passivation of the perovskite surface and bulk phase.

[0007] The first objective of this invention is to provide a method for fabricating a solution-induced monolithic passivated perovskite solar cell, comprising the following steps:

[0008] S1. Preparation of Cs using solvents with different boiling points 0.35 FA 0.65 Pb(I 0.6 Br 0.4 )3 Perovskite precursor solution;

[0009] S2. Add MeO-4pacz to the FTO substrate, spin-coat and anneal to obtain the hole transport layer;

[0010] S3. Spin-coating Cs onto the surface of the hole transport layer obtained in step S2. 0.35 FA 0.65 Pb(I 0.6 Br 0.4 )3 Perovskite precursor solution, spin-coated in steps, with anti-solvent added dropwise during spin-coating, followed by annealing to obtain perovskite light-absorbing layer;

[0011] S4. Add a passivating agent to the perovskite light-absorbing layer obtained in step S3, spin-coat and anneal; repeat once to obtain a passivation layer;

[0012] S5. An electron transport layer and an electrode are sequentially fabricated on the passivation layer to finally obtain the integrated perovskite solar cell.

[0013] In some embodiments of the present invention, in step S1, the solvents with different boiling points include DMF, DMSO and NMP, and the volume ratio of DMF, DMSO and NMP is (6~8):(1~2):1.

[0014] In some embodiments of the present invention, in step S2, the spin coating speed is 3000~5000 r / s, the acceleration is 1500~2500 r / s, and the spin coating time is 30~35 seconds.

[0015] In some embodiments of the present invention, in step S2, the annealing temperature is 100~105°C and the time is 5~10 min.

[0016] In some embodiments of the present invention, step S3, the spin coating process includes two steps: the first step is to rotate on a spin coater at a speed of 1500~2500 r / s and an acceleration of 1000~2000 r / s for 5~10 seconds; the second step is to rotate at a speed of 5000~6000 r / s and an acceleration of 1500~2500 r / s for 30~35 seconds.

[0017] In some embodiments of the present invention, in step S3, the antisolvent is added when the countdown is between 20 and 25 seconds;

[0018] The antisolvents include one or more of anisole, chlorobenzene, and ethyl acetate.

[0019] In some embodiments of the present invention, in step S3, the annealing temperature is 100~105℃ and the annealing time is 10~20min.

[0020] In some embodiments of the present invention, in step S4, the spin coating speed is 2500~3500 r / s, the acceleration is 1500~2500 r / s, the spin coating time is 30 seconds; the annealing temperature is 100~105℃, and the annealing time is 5~10 min.

[0021] In some embodiments of the present invention, in step S4, the passivating agent includes one or more of PEAI, PDADI, ODADI and EDAI2.

[0022] A second objective of this invention is to provide an integrated passivated perovskite solar cell prepared by the aforementioned method.

[0023] The beneficial effects of this invention are:

[0024] This invention introduces several solvents with different boiling points into the perovskite precursor solution. During the annealing process of the perovskite layer, the high-boiling-point small molecule solvents are evaporated using their different boiling points, leaving channels in the perovskite bulk phase for passivating agents to enter.

[0025] This invention utilizes the different boiling points of different solvents to evaporate high-boiling-point small-molecule solvents during annealing, leaving channels for passivating agents to enter during crystal formation, thus achieving one-piece passivation of perovskite, which is simple to operate.

[0026] This invention optimizes surface and bulk defects in perovskites, thereby improving the photoelectric performance of perovskite solar cells.

[0027] The perovskite solar cells produced by this invention maintain high photoelectric performance even after long-term storage, greatly improving the stability of perovskite solar cells. Attached Figure Description

[0028] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein...

[0029] Figure 1 This is a scanning electron microscope image of the untreated perovskite thin film in Comparative Example 1 of this invention.

[0030] Figure 2 This is a scanning electron microscope image of a perovskite thin film treated with NMP and passivating agent according to Example 1 of the present invention.

[0031] Figure 3 These are the current-voltage (JV) characteristic curves of the perovskite solar cells of Example 1 (treated) and Comparative Example 3 (untreated).

[0032] Figure 4 This is a stability test of the perovskite solar cells of Example 1 (treated) and Comparative Example 3 (untreated) of the present invention. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0034] Example 1

[0035] This embodiment provides a method for fabricating a solution-induced monolithic passivated perovskite solar cell, as detailed below:

[0036] S1, in creating Cs 0.35 FA 0.65 Pb(I0.6 Br 0.4 3. When preparing perovskite precursor solutions, a 1.2 MCs concentration was prepared using a mixed solvent of DMF:DMSO:NMP = 8:1:1 (v / v / v). 0.35 FA 0.65 Pb(I 0.6 Br 0.4 The perovskite precursor solution of 3 was prepared by using CsI, FAI, PbBr2, and PbI2 as raw materials and reagents. The concentrations of CsI, FAI, PbBr2, and PbI2 were 0.42 mol / L, 0.78 mol / L, 0.72 mol / L, and 0.48 mol / L, respectively. The solutions were mixed thoroughly.

[0037] S2. Spin-coating the hole transport layer MeO-4PACz: 50 μL of MeO-4pacz was dropped onto an FTO substrate and rotated on a spin coater at a speed of 4000 r / s and an acceleration of 2000 r / s for 30 seconds. The substrate was then annealed at 100℃ for 10 min to obtain the hole transport layer.

[0038] S3. Fabrication of the perovskite light-absorbing layer: Spin-coat the surface of the hole transport layer obtained in step S2 with a perovskite precursor solution. Add 80 mL of the perovskite precursor solution obtained in step S1 to each substrate. The spin-coating process consists of two steps: First, spin-coat the substrate at a speed of 2000 r / s and an acceleration of 2000 r / s for 5 seconds; second, spin-coat the substrate at a speed of 6000 r / s and an acceleration of 2000 r / s for 30 seconds. When the countdown is between 20 and 25 seconds, add 200 μL of the anti-solvent anisole to each substrate. Then anneal at 100℃ for 15 min to obtain the perovskite light-absorbing layer.

[0039] S4. Spin-coating passivation layer: 50 μL of passivating agent PEAI is dropped onto the perovskite light-absorbing layer, and the layer is spin-coated at 3000 r / s and 2000 r / s for 30 seconds. It is then annealed at 105℃ for 5 min. After PEAI annealing, a second passivating agent PDADI is prepared using the same steps; thus, the passivation layer is obtained.

[0040] S5, spin coating of electron transport layer PCBM: rotate at a speed of 2000r / s and an acceleration of 1000r / s for 30 seconds on a spin coater. When the countdown is 20-25 seconds, dynamically drop 80μL of PCBM (fullerene C60 derivative PC

[60] BM) onto the passivation layer obtained in step S4.

[0041] S6. Electrode Fabrication: Transfer the substrate prepared according to the above steps to a thermal evaporation apparatus, and deposit a 100-120 nm thick silver electrode at an evaporation rate of 0.7 nm / s. The evaporation source is silver, and the evaporation pressure is 1 × 10⁻⁶. -5 Pa.

[0042] Comparative Example 1

[0043] This comparative example provides a perovskite thin film that has not undergone high-boiling-point small molecule solvent addition or passivation treatment.

[0044] Comparative Example 2

[0045] This comparative example provides a perovskite thin film that has undergone high-boiling-point small molecule solvent addition treatment but has not been passivated.

[0046] Comparative Example 3

[0047] This comparative example provides a perovskite thin film that has undergone passivation treatment without the addition of high-boiling-point small molecule solvents.

[0048] Performance testing

[0049] (1) The current-voltage characteristic (JV) curves of the perovskite solar cells obtained in Example 1 and Comparative Example 3 are shown in the figure. Figure 3 ,Depend on Figure 3 It can be seen that after adding high-boiling-point small molecule solvents and passivation treatment, the open-circuit voltage of perovskite solar cells can be significantly improved, thereby improving device efficiency.

[0050] (2) The perovskite solar cells prepared in Example 1 and Comparative Example 3 were subjected to stability testing. Specifically, they were placed in a nitrogen atmosphere, and efficiency tests were conducted at the same time intervals. The experimental results are shown below. Figure 4 As shown in the figure, the device after adding high-boiling-point small molecule solvent and passivation treatment can still maintain 96.81% of the initial efficiency after 2000h, while the device without the addition of high-boiling-point small molecule solvent has decreased to 71.82% of the initial efficiency after 2000h, indicating that the stability of the treated device is greatly improved.

[0051] The embodiments described above are merely preferred embodiments for fully illustrating the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention.

Claims

1. A method for fabricating a solution-induced monolithic passivated perovskite solar cell, characterized in that, Includes the following steps: S1. Preparation of Cs using solvents with different boiling points 0.35 FA 0.65 Pb(I 0.6 Br 0.4 )3 Perovskite precursor solution; S2. Add MeO-4pacz to the FTO substrate, spin-coat and anneal to obtain the hole transport layer; S3. Spin-coating Cs onto the surface of the hole transport layer obtained in step S2. 0.35 FA 0.65 Pb(I 0.6 Br 0.4 )3 Perovskite precursor solution, spin-coated in steps, with anti-solvent added dropwise during spin-coating, followed by annealing to obtain perovskite light-absorbing layer; S4. Add a passivating agent to the perovskite light-absorbing layer obtained in step S3, spin-coat and anneal; repeat once to obtain a passivation layer; S5. An electron transport layer and an electrode are sequentially fabricated on the passivation layer to finally obtain the integrated perovskite solar cell.

2. The preparation according to claim 1, characterized in that, In step S1, the solvents with different boiling points include DMF, DMSO and NMP, and the volume ratio of DMF, DMSO and NMP is (6~8):(1~2):

1.

3. The preparation according to claim 1, characterized in that, In step S2, the spin coating speed is 3000~5000 r / s, the acceleration is 1500~2500 r / s, and the spin coating time is 30~35 seconds.

4. The preparation according to claim 1, characterized in that, In step S2, the annealing temperature is 100~105℃ and the time is 5~10min.

5. The preparation according to claim 1, characterized in that, In step S3, the spin coating process includes two steps: the first step is to rotate on a spin coater at a speed of 1500~2500 r / s and an acceleration of 1000~2000 r / s for 5~10 seconds; the second step is to rotate at a speed of 5000~6000 r / s and an acceleration of 1500~2500 r / s for 30~35 seconds.

6. The preparation according to claim 1, characterized in that, In step S3, the antisolvent is added when the countdown is between 20 and 25 seconds. The antisolvents include one or more of anisole, chlorobenzene, and ethyl acetate.

7. The preparation according to claim 1, characterized in that, In step S3, the annealing temperature is 100~105℃ and the annealing time is 10~20min.

8. The preparation according to claim 1, characterized in that, In step S4, the spin coating speed is 2500~3500 r / s, the acceleration is 1500~2500 r / s, and the spin coating time is 30 seconds; the annealing temperature is 100~105℃, and the annealing time is 5~10 min.

9. The preparation according to claim 1, characterized in that, In step S4, the passivating agent includes one or more of PEAI, PDADI, ODADI, and EDAI2.

10. An integrated passivated perovskite solar cell, characterized in that, Prepared by the method described in any one of claims 1 to 9.

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