Band Alignment Engineering Towards High Efficiency Carbon‐Based Inorganic Planar CsPbIBr2 Perovskite Solar Cells

• DOI: 10.1002/cssc.201900611
• Publication Date: 2019-03-26T12:08:23Z
• Authors: Weidong Zhu; Zeyang Zhang; Wenming Chai; Qianni Zhang; Dazheng Chen; Zhenhua Lin; Jingjing Chang; Jincheng Zhang; Chunfu Zhang; Yue Hao
• Keywords: Charge carrier; Carbon fibers; Open-circuit voltage; Hybrid solar cell

Perovskite CsPbIBr2 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 cells fabricated with this active layer, which intrinsically associated the unwanted conduction misalignment between commonly used TiO2 electron transport has limited power conversion efficiency (PCE) values. Herein, we demonstrate successful alignment engineering at /CsPbIBr2 heterojunction by modifying CsBr clusters. Such modification triggers a beneficial increase minimum (CBM) from -4.00 -3.81 eV decreases work function 4.11 3.86 eV, thus promoting favorable heterojunction, suppressing recombination, improving extraction carriers. As result, exhibit over 20 % enhancement average PCE. The champion device achieves PCE 10.71 %, record among pure -based open-circuit voltage 1.261 V, excellent stability.