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Surface Electronic Modification of Perovskite Thin Film with Water‐Resistant Electron Delocalized Molecules for Stable and Efficient Photovoltaics
Author(s) -
Wen Tian Yu,
Yang Shuang,
Liu Peng Fei,
Tang Li Juan,
Qiao Hong Wei,
Chen Xiao,
Yang Xiao Hua,
Hou Yu,
Yang Hua Gui
Publication year - 2018
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.201703143
Subject(s) - materials science , surface modification , perovskite (structure) , energy conversion efficiency , chemical engineering , delocalized electron , photovoltaics , nanotechnology , molecule , photovoltaic system , optoelectronics , organic chemistry , chemistry , ecology , engineering , biology
Although the efficiency of perovskite solar cells (PSCs) is close to crystalline silicon solar cells, the instability of perovskite, especially in humid condition, still hinders its commercialization. As an effective method to improve their stability, surface functionalization, by using hydrophobic molecules, has been extensively investigated, but usually accompanied with the loss of device efficiencies owing to their intrinsic electrical insulation. In this work, for the first time, it is demonstrated that 3‐alkylthiophene‐based hydrophobic molecules can be used as both water‐resistant and interface‐modified layers, which could simultaneously enhance both stability and performance significantly. Benefitting from their unique structures of thiophene rings, the π‐electrons are highly delocalized and thus enhance the charge transfer and collection at the interface. The device based on 3‐hexylthiophene treatment exhibits a champion energy conversion efficiency of 19.89% with a dramatic 10% enhancement compared with the pristine one (18.08%) of Cs 0.05 FA 0.81 MA 0.14 PbBr 0.45 I 2.55 ‐based PSCs. More importantly, the degradation of the long‐term efficiency of unsealed device is less than 20% in Cs 0.05 FA 0.81 MA 0.14 PbBr 0.45 I 2.55 ‐based PSCs after more than 700 h storage in air. This finding provides an avenue for further improvement of both the efficiency and stability of PSCs.