Smelting recrystallization of CsPbBrI2 perovskites for indoor and outdoor photovoltaics
Kai‐Li Wang, Yingguo Yang, Yanhui Lou, Meng Li, Femi Igbari, Junjie Cao, Jing Chen, Wenfan Yang, Chong Dong, Lina Li, Renzhong Tai, Zhao‐Kui Wang
Abstract
A smelting multiple recrystallization strategy and its effects on the morphology, composition, and defects of CsPbBrI2 film were investigated. An optimal number (n = 2) of recrystallization cycles improved the crystallinity and phase purity, minimized the grain boundaries, and optimized the crystal structure, yielding a high-quality perovskite film with significantly reduced defects density. The corresponding photovoltaic devices exhibited a champion efficiency of 16.02% under AM 1.5 G illumination and presented an even higher indoor efficiency of 33.50% under an LED (2956 K, Pin: 334.41 μW/cm2). This recrystallization method offers a promising strategy for developing high-performance indoor and outdoor photovoltaics. Direct recrystallization in the cells was also explored to achieve enhanced stability and longer lifetime in humid conditions.