Strain‐Stabilized CsPbI<sub>3</sub> Perovskite via Organopolysilazane for Efficient Solar Cells with Efficiency over 19%
Haixuan Yu, Xiongjie Li, Zhiguo Zhang, Huaxia Ban, Xiu Gong, Zhirong Liu, Miaomiao Zhang, Qiang Sun, Tao Zhang, Yan Shen, Xiaoli Zhang, Jun Zhu, Mingkui Wang
Abstract
Abstract Principally, all‐inorganic perovskite crystals, such as CsPbI 3 , possess higher thermal stability than their organic–inorganic hybrid counterparts, like CH 3 NH 3 PbI 3 , due to the type of chemical bond variants. However, considering a retained strain in these stiff films, it is a challenge to stabilize CsPbI 3 within the photoactive phase for photovoltaic application under ambient conditions. This article reports organopolysilazane (OPSZ) as a strain compensation layer that regulates the tense strain during the annealing process, a very attractive feature for all‐inorganic perovskite solar cells with a CsPbI 3 active layer. When depositing OPSZ onto the surface of CsPbI 3 film for thin‐film solar cell devices with FTO/c‐TiO 2 /CsPbI 3 /spiro‐OMeTAD/Au architecture, an efficiency of 19.12% is achieved under standard illumination test conditions. This strain compensation layer offers a viable pathway to develop efficient and stable solar cells with inorganic perovskite crystalline thin films for scale‐up and practical applications.