Premium
Limiting Perovskite Solar Cell Performance by Heterogeneous Carrier Extraction
Author(s) -
Tian Wenming,
Cui Rongrong,
Leng Jing,
Liu Junxue,
Li Yajuan,
Zhao Chunyi,
Zhang Jun,
Deng Weiqiao,
Lian Tianquan,
Jin Shengye
Publication year - 2016
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201606574
Subject(s) - perovskite (structure) , crystallite , grain boundary , materials science , perovskite solar cell , energy conversion efficiency , photoluminescence , carrier lifetime , solar cell , grain size , electrode , homogeneity (statistics) , optoelectronics , chemical physics , mineralogy , chemical engineering , crystallography , chemistry , silicon , microstructure , composite material , statistics , mathematics , engineering , metallurgy
Although the power conversion efficiency of perovskite solar cells has improved rapidly, a rational path for further improvement remains unclear. The effect of large morphological heterogeneity of polycrystalline perovskite films on their device performance by photoluminescence (PL) microscopy has now been studied. Contrary to the common belief on the deleterious effect of morphological heterogeneity on carrier lifetimes and diffusivities, in neat CH 3 NH 3 PbI 3 (Cl) polycrystalline perovskite films, the local (intra‐grain) carrier diffusivities in different grains are all surprisingly high (1.5 to 3.3 cm 2 s −1 ; comparable to bulk single‐crystals), and the local carrier lifetimes are long (ca. 200 ns) and surprisingly homogenous among grains, and uniform across grain boundary and interior. However, there is a large heterogeneity of carrier extraction efficiency at the perovskite grain–electrode interface. Improving homogeneity at perovskite grain–electrode contacts is thus a promising direction for improving the performance of perovskite thin‐film solar cells.