Research On Crystallization Regulation Of Large-area Perovskite Films For High-performance Solar Modules

To achieve the industrial application of perovskite solar cells（PSCs）,it not only requires the transfer of the fabrication process of PSCs from environmentally controllable glove boxes to the air,but also urgently needs the scale-up of laboratory-scale PSCs to large-area modules with high power conversion efficiency（PCE）.However,the high sensitivity of perovskite to air humidity makes it difficult to control the quality of large-area FA-based perovskite film,resulting in the efficiency of large-area perovskite solar modules（PSMs）lagged behind laboratory-scale PSCs.Therefore,the main work of this dissertation focuses on improving the film-forming quality of large-area perovskite films in air,and optimizing the scalable fabrication process to improve the performance of PSMs.Firstly,a strategy to improve the film formation quality of perovskite films is proposed in an environmentally controllable glove box,which is beneficial to achieve the fabrication of high-performance large-area PSCs;Secondly,the film-forming quality of perovskite in air is optimized by solvent engineering and component engineering,thus achieving the preparation of high-efficiency inverted structure PSCs in air;Then,the scale-up of PSCs to PSMs is achieved in air by optimizing scalable processes;Finally,the efficiency of 10×10 cm² inverted PSMs is improved to over 20%by efficient additive strategies,which further demonstrates good outdoor applications.The detailed results are listed as follows:1.The film-forming quality of double cations（Cs FA）based perovskite film is improved by a 2-fluorothiophenol（FTP）additive with Lewis base properties.It not only could passivate defects and optimize crystal orientation in perovskite films,but also could improve their hydrophobicity.As a result,the efficiency of the regular PSCs with an effective area of 0.04 cm² is increased from 20.3%to 22.66%.And the efficiency of device is increased from 16.86%to 20.01%after expanding this strategy to a 1cm² PSCs.Finally,the efficiency of the FTP-modified photovoltaic cells without any encapsulation still maintains 90%of their initial efficiency even after aging for 80 days under air conditions,proving that this strategy can improve the humidity stability of perovskite photovoltaic cells.2.Optimizing the processes of magnetron sputtering of NiO_x films and perovskite precursor solvents is of great significant for achieving highly-efficient scalable manufactured PSCs in air.Moreover,perovskite compositions are optimized to further improve the photoelectric performance of perovskite films.Finally,the Cs FA and triple cations（Cs FAMA）based inverted PSCs are fabricated in air,with the PCE of 17.17%and 18.94%（active area of 0.04 cm²）,respectively.3.10×10 cm² PSMs with an active area of 57.3 cm² obtain a champion PCE of12.95%by optimizing laser parameters and slot-die coated processes.Furthermore,the photoelectric performance of large-area perovskite films is improved by adding Lewis-based 4-Chlorobenzoic acid（4-CBA）additive in perovskite precursor solution,which can increase the grain size and passivate defects of large-area films.Based on this strategy,the PCE of the 10×10 cm² inverted Cs FA-and Cs FAMA-based PSMs are further improved to 15.08%and 16.48%,respectively.4.The crystallization process of perovskite at different stages in the entire slot-die coating process has been regulated by adding Pyrrodiazole（PZ）additive into the perovskite precursor solution,which can interact with both FAI and Pb I₂ showing an immobilization effect.PZ could regulate the nucleation and crystallization processes of perovskite in air,thus improving the grain size and uniformity of 10×10 cm² perovskite films,and further enhancing the photoelectric performance of films.As a result,the efficiency of the 10×10 cm² Cs FAMA-based inverted PSMs is further improved to 18.84%（certified efficiency:18.1%）.Moreover,PZ modified PSMs show excellent work stability.Especially for the encapsulated modules,which can still maintain at 94%of the initial value after 1000 h of continuous light aging in air.5.To obtain more stable and high-efficiency PSMs,the performances of Cs FA-based PSMs are further optimized by introducing PCBM/chlorobenzene solution into the perovskite precursor solution.This strategy can passivate the defects and enhance the crystal quality of 10×10 cm² perovskite films.As a result,the efficiency of 10×10 cm²inverted PSMs is further increased to 20.15%,and the encapsulated module can still maintain above 90%of the initial efficiency after exposing to light soaking for 1500 h in air.Finally,42 perovskite photovoltaic modules are connected in combined series and parallel manner,which demonstrates good working stability as the battery can be charged by solar lights.