Premium
High‐Efficiency CsPbI 2 Br Perovskite Solar Cells with Dopant‐Free Poly(3‐hexylthiophene) Hole Transporting Layers
Author(s) -
Li MingHua,
Liu ShunChang,
Qiu FaZheng,
Zhang ZhenYun,
Xue DingJiang,
Hu JinSong
Publication year - 2020
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.202000501
Subject(s) - dopant , materials science , energy conversion efficiency , perovskite (structure) , nucleation , layer (electronics) , crystallization , chemical engineering , optoelectronics , solution process , nanotechnology , doping , organic chemistry , engineering , chemistry
CsPbI 2 Br is emerging as a promising all‐inorganic material for perovskite solar cells (PSCs) due to its more stable lattice structure and moisture resistance compared to CsPbI 3 , although its device performance is still much behind this counterpart. Herein, a preannealing process is developed and systematically investigated to achieve high‐quality CsPbI 2 Br films by regulating the nucleation and crystallization of perovskite. The preannealing temperature and time are specifically optimized for a dopant‐free poly(3‐hexylthiophene) (P3HT)‐based device to target dopant‐induced drastic performance degradation for spiro‐OMeTAD‐based devices. The resulting P3HT‐based device exhibits comparable power conversion efficiency (PCE) to spiro‐OMeTAD‐based devices but much enhanced ambient stability with over 95% PCE after 1300 h. A diphenylamine derivative is introduced as a buffer layer to improve the energy‐level mismatch between CsPbI 2 Br and P3HT. A record‐high PCE of 15.50% for dopant‐free P3HT‐based CsPbI 2 Br PSCs is achieved by alleviating the open‐circuit voltage loss with the buffer layer. These results demonstrate that the preannealing processing together with a suitable buffer layer are applicable strategies for developing dopant‐free P3HT PSCs with high efficiency and stability.