The perovskite solar cell (PSC) is a photovoltaic device with a over 23.7% power conversion efficiency (PCE). With high energy conversion efficiencies and low manufacturing cost, it has great potential for the future commercialization. However, the low device stability hinders its further application.<br/><br/>The interactions of hole transport layer components, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and 4-tert-butylpyridine (tBP), limit the improvement of perovskite stability. In our study, the interactions and impacts of hole transport layer components with perovskite in PSCs had been unveiled. The formation of tBP-LiTFSI complexes was investigated which shows that the tBP-LiTFSI complexes can alleviate the negative effects of the individual components in PSCs while maintaining the positive effects. With the understanding of formation of tBP-LiTFSI complexes, we changed the tBP:LiTFSI ratio in PSCs. The PSCs fabricated with the suggested tBP:LiTFSI ratio have decreased efficiency variation and enhanced device stability. Moreover, the influences of thin film deposition methods on hole transport layer interfaces were investigated. Due to the formation of tBP-LiTFSI, these deposion methods can result in different hole transport layer interface. The understanding of roles for hole transport layer components in PSCs shows the way for further improvements to device performance.<br/>

Functions and interactions of hole transport layer components in perovskite solar cells

2019 Fall National Meeting

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