Open AccessDopant‐Free Crossconjugated Hole‐Transporting Polymers for Highly Efficient Perovskite Solar Cells
Author(s) -
Sun Xianglang,
Deng Xiang,
Li Zhen,
Xiong Bijin,
Zhong Cheng,
Zhu Zonglong,
Li Zhong'an,
Jen Alex K.Y.
Publication year - 2020
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.201903331
Subject(s) - dopant , materials science , perovskite (structure) , crystallization , energy conversion efficiency , polymer , wetting , nanotechnology , fabrication , grain size , optoelectronics , chemical engineering , doping , composite material , medicine , alternative medicine , pathology , engineering
Currently, there are only very few dopant‐free polymer hole‐transporting materials (HTMs) that can enable perovskite solar cells (PVSCs) to demonstrate a high power conversion efficiency (PCE) of greater than 20%. To address this need, a simple and efficient way is developed to synthesize novel crossconjugated polymers as high performance dopant‐free HTMs to endow PVSCs with a high PCE of 21.3%, which is among the highest values reported for single‐junction inverted PVSCs. More importantly, rational understanding of the reasons why two isomeric polymer HTMs ( PPE1 and PPE2 ) with almost identical photophysical properties, hole‐transporting ability, and surface wettability deliver so distinctly different device performance under similar device fabrication conditions is manifested. PPE2 is found to improve the quality of perovskite films cast on top with larger grain sizes and more oriented crystallization. These results help unveil the new HTM design rules to influence the perovskite growth/crystallization for improving the performance of inverted PVSCs.