An Intermediate-Aided Perovskite Phase Purification for High-Performance Solar Cells
Jinghao Ge, Yiru Huang, Xuexiao Chen, Yong Wang, Hanqing Zeng, Yiran Tao, Zixin Zeng, Lu Zhang, Lu Zhang, Lei Zhang, Lei Zhang, Xinhui Lu, Sai‐Wing Tsang, Jiaxue You, Alex K.‐Y. Jen, Shengzhong Liu
Abstract
In recent years, perovskite solar cells (PSCs) have garnered considerable attention as a prime candidate for next-generation photovoltaic technology. Ensuring the structural stability of perovskites is crucial to the operational reliability of these devices. However, the nonphotoactive yellow phase (δ-FAPbI 3 ) of formamidine (FA)-based perovskites is more favorable in thermodynamics, making it challenging to achieve pure α phase in crystallization. Herein, we introduce a language machine learning approach to analyze suitable additives to achieve the desired phase purification. By fast analyzing ∼10 6 abstracts in chemistry and materials science, our approach identifies aminoguanidine (AG) hydrochloride as a promising candidate for intermediate phase formation during nucleation. The experiments confirm that AG forms a novel one-dimensional intermediate phase (AGPbI 3 ), which suppresses the solvent intermediate phase and δ-phase formation and promotes development of the α-phase. Consequently, the efficiency of the solar cells increased from 23.99 to 25.46%. The long-term thermal stability and photostability were significantly enhanced owing to the purified α-phase, maintaining 82% of the initial efficiency after 1056 h aging at 85 °C and 94.6% of the initial efficiency after 835 h of illumination in an N 2 atmosphere, respectively. This strategy also enhanced the performance of flexible solar cells, increasing their efficiency from 21.24 to 22.86%. This work is designed to fast explore new intermediate phases in improving the efficiency and operation stability of thin-film solar cells.