Premium
Band Alignment Engineering Towards High Efficiency Carbon‐Based Inorganic Planar CsPbIBr 2 Perovskite Solar Cells
Author(s) -
Zhu Weidong,
Zhang Zeyang,
Chai Wenming,
Zhang Qianni,
Chen Dazheng,
Lin Zhenhua,
Chang Jingjing,
Zhang Jincheng,
Zhang Chunfu,
Hao Yue
Publication year - 2019
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201900611
Subject(s) - heterojunction , materials science , optoelectronics , perovskite (structure) , band gap , energy conversion efficiency , work function , charge carrier , carbon fibers , conduction band , open circuit voltage , hybrid solar cell , nanotechnology , electron , polymer solar cell , voltage , chemical engineering , layer (electronics) , composite number , electrical engineering , physics , quantum mechanics , engineering , composite material
Abstract Perovskite CsPbIBr 2 is attracting ever‐increasing attention for carbon‐based, all‐inorganic solar cells, owing to its well‐balanced band gap and stability features. However, significant interfacial recombination of charge carriers in solar cells fabricated with this active layer, which is intrinsically associated with the unwanted conduction band misalignment between CsPbIBr 2 and the commonly used TiO 2 electron transport layer, has limited power conversion efficiency (PCE) values. Herein, we demonstrate successful conduction band alignment engineering at the TiO 2 /CsPbIBr 2 heterojunction by modifying TiO 2 with CsBr clusters. Such modification triggers a beneficial increase in the conduction band minimum (CBM) of TiO 2 from −4.00 to −3.81 eV and decreases the work function from 4.11 to 3.86 eV, thus promoting favorable band alignment at the heterojunction, suppressing recombination, and improving extraction and transport of charge carriers. As a result, the carbon‐based, all‐inorganic CsPbIBr 2 solar cells exhibit over 20 % enhancement in average PCE. The champion device achieves a PCE of 10.71 %, a record among pure CsPbIBr 2 ‐based cells, open‐circuit voltage of 1.261 V, and excellent stability.