Antioxidant Grain Passivation for Air-Stable Tin-Based Perovskite Solar Cells

作者：Tai, Qidong; Guo, Xuyun; Tang, Guanqi; You, Peng; Ng, Tsz-Wai; Shen, Dong; Cao, Jiupeng; Liu, Chun-Ki; Wang, Naixiang; Zhu, Ye; Lee, Chun-Sing; Yan, Feng^*

来源：Angewandte Chemie - International Edition, 2019, 58(3): 806-810.

DOI：10.1002/anie.201811539

• antioxidants
• perovskite phases
• solar cells
• tin

Tin-based perovskites with excellent optoelectronic properties and suitable band gaps are promising candidates for the preparation of efficient lead-free perovskite solar cells (PSCs). However, it is challenging to prepare highly stable and efficient tin-based PSCs because Sn2+ in perovskites can be easily oxidized to Sn4+ upon air exposure. Here we report the fabrication of air-stable FASnI(3) solar cells by introducing hydroxybenzene sulfonic acid or its salt as an antioxidant additive into the perovskite precursor solution along with excess SnCl2. The interaction between the sulfonate group and the Sn2+ ion enables the in situ encapsulation of the perovskite grains with a SnCl2-additive complex layer, which results in greatly enhanced oxidation stability of the perovskite film. The corresponding PSCs are able to maintain 80 % of the efficiency over 500 h upon air exposure without encapsulation, which is over ten times longer than the best result reported previously. Our results suggest a possible strategy for the future design of efficient and stable tin-based PSCs.

• 出版日期2019-1-14