Premium
Ultrathin Nanosheets of Oxo‐functionalized Graphene Inhibit the Ion Migration in Perovskite Solar Cells
Author(s) -
Li Meng,
Zuo WeiWei,
Wang Qiong,
Wang KaiLi,
Zhuo MingPeng,
Köbler Hans,
Halbig Christian E.,
Eigler Siegfried,
Yang YingGuo,
Gao XingYu,
Wang ZhaoKui,
Li Yongfang,
Abate Antonio
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.201902653
Subject(s) - materials science , perovskite (structure) , formamidinium , graphene , energy conversion efficiency , ionic bonding , chemical engineering , phase (matter) , nanotechnology , ion , optoelectronics , organic chemistry , chemistry , engineering
Mixed cation/halide perovskites have led to a significant increase in the efficiency and stability of perovskite solar cells. However, mobile ionic defects inevitably exacerbate the photoinduced phase segregation and self‐decomposition of the crystal structure. Herein, ultrathin 2D nanosheets of oxo‐functionalized graphene/dodecylamine (oxo‐G/DA) are used to solve ion migration in cesium (Cs)‐formamidinium (FA)‐methylammonium (MA) triple‐cation‐based perovskites. Based on the superconducting carbon skeleton and functional groups that provide lone pairs of electrons on it, the ultrathin 2D network structure can fit tightly on the crystals and wrap them, isolating them, and thus reducing the migration of ions within the built‐in electric field of the perovskite film. As evidence of the formation of sharp crystals with different orientation within the perovskite film, moiré fringes are observed in transmission electron microscopy. Thus, a champion device with a power conversion efficiency (PCE) of 21.1% (the efficiency distribution is 18.8 ± 1.7%) and a remarkable fill factor of 81%, with reduced hysteresis and improved long‐term stability, is reported. This work provides a simple method for the improvement of the structural stability of perovskite in solar cells.