Triphenylphosphine oxide additive regulates the growth of perovskite films by evaporation-spraying technique for high-efficiency large-area solar cell modules
Mingwei Zhu, Danlin Ruan, Xin Zhao, Jiawei Song, Jiahao Cheng, Wenjian Shen, Wangnan Li, Guijie Liang, Ying Liang, Yong Peng, Bin Li, Yi‐Bing Cheng
Abstract
Premature perovskite films rapidly form at the FAI/PbI 2 interface, inhibiting further reactions between FAI and PbI 2 during the fabrication of perovskite films via the evaporating-spraying hybrid method according to our previous research. In this research, triphenylphosphine oxide (TPPO) was proved to be an effective coordinator that reduces the reaction rate between FAI and PbI 2 at the initial stage, which can be attributed to the hydrogen (H) bonds between FA + and TPPO , and coordinate bonds between TPPO and PbI 2 . Additionally, the quality of perovskite films improved significantly: the trap state density decreased from 1.6 × 10 18 to 3.17 × 10 17 cm −3 , while the crystal size increased from 740 to 940 nm. The champion perovskite device achieved a remarkable efficiency of 20.93% (0.09 cm 2 ) and 16.75% (63.7 cm 2 ), marking one of the highest reported results for the evaporating-spraying hybrid method. Moreover, the perovskite solar cells retained over 80% of their initial performances after 600 h of storage at 60 °C in a nitrogen environment without encapsulation. It also maintained approximately 90% of its initial performance after continuous illumination at 25 °C for 1400 h under the same conditions.