题目：

Spring-Like Ammonium Salt Assisting Stress Release for  Low-Temperature Deposited FAPbI3 Films Toward Flexible Photovoltaic Application

作者：

Chun-Hao Chen, Fan Hu, Zhen-Huang Su, Yan-Jun Yu, Kai-Li Wang, Yi-Ran Shi, Jing Chen, Yu Xia, Xing-Yu Gao, Zhao-Kui Wang*, Liang-Sheng Liao

摘要：

The substrates of conventional flexible perovskite solar cells (FPSCs) are thermoplastic polymer material polyethylene naphthalate (PEN), which will deform during high temperature annealing process. In addition, lead iodide (PbI2) permanently formed and the substrate undergoes reversible deformation from 20 °C to 200 °C and back to 20 °C. Therefore, to balance the substrate supporting capacity and the crystalline quality of narrow band gap α-phase formamidinium lead iodide (α-FAPbI3), an annealing process of 120 °C for 30 minutes is determined. Additionally, there will also be a large number of gaps and lattice strain at the perovskite grain boundaries during the annealing process as the FAPbI3 phase transition is accompanied by much lattice shrinkage. As a result, 1,6-hexanediammonium diiodide (HADI) is chosen to passivate the defects and release the stress of perovskite film. Therefore, a recorded 1.4% extended stretch rate of the flexible film is attained. Finally, the champion PCE of 21.14% under AM 1.5G and 31.52% under 1062 lux is achieved after HADI treatment, accompanied by a better long-term and mechanical stability. This study provides annealing process optimization and stress relief strategies for the further development of narrow band gap FPSCs.

影响因子：

19.924

分区情况：

一区