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High‐Purity Inorganic Perovskite Films for Solar Cells with 9.72 % Efficiency
Author(s) -
Duan Jialong,
Zhao Yuanyuan,
He Benlin,
Tang Qunwei
Publication year - 2018
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201800019
Subject(s) - perovskite (structure) , energy conversion efficiency , materials science , perovskite solar cell , relative humidity , solar cell , monolayer , chemical engineering , optoelectronics , nanotechnology , physics , engineering , thermodynamics
All‐inorganic perovskite solar cells with high efficiency and improved stability are promising for commercialization. A multistep solution‐processing method was developed to fabricate high‐purity inorganic CsPbBr 3 perovskite films for use in efficient solar cells. By tuning the number of deposition cycles ( n ) of a CsBr solution, the phase conversion from CsPb 2 Br 5 ( n ≤3), to CsPbBr 3 ( n= 4), and Cs 4 PbBr 6 ( n ≥5) was optimized to achieve vertical‐ and monolayer‐aligned grains. Upon interfacial modification with graphene quantum dots, the all‐inorganic perovskite solar cell (without a hole‐transporting layer) achieved a power conversion efficiency (PCE) as high as 9.72 % under standard solar illumination conditions. Under challenging conditions, such as 90 % relative humidity (RH) at 25 °C or 80 °C at zero humidity, the optimized device retained 87 % PCE over 130 days or 95 % over 40 days, compared to the initial efficiency.