High‐Performance Perovskite Solar Cells with Enhanced Environmental Stability Based on a (p‐FC6H4C2H4NH3)2[PbI4] Capping Layer

By Qin Zhou, Lusheng Liang, Junjie Hu, Bingbing Cao, Longkai Yang, Tingjun Wu, Xin Li, Bao Zhang, P. Gao. Advanced Energy Materials, 2019

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Supported by the density functional theory (DFT) calculations, for the first time, a fluorinated aromatic cation, 2‐(4‐fluorophenyl)ethyl ammonium iodide (FPEAI), is introduced to grow in situ a low dimensional perovskite layer atop 3D perovskite film with excess PbI2. The resulted (p‐FC6H4C2H4NH3)2[PbI4] perovskite functions as a protective capping layer to protect the 3D perovskite from moisture. In the meantime, the thin layer facilitates charge transfer at the interfaces, thereby reducing the nonradiative recombination pathways. Laser scanning confocal microscopy unveils visually the distribution of the 2D perovskite layer on top of the 3D perovskite. When employing the 3D–2D perovskite as the absorbing layer in the photovoltaic cells, a high power conversion efficiency of 20.54% is realized. Superior device performance and moisture stability are observed with the modified perovskite over the whole stability test period.

Subfields: Electrical and Electronic Engineering, Electronic, Optical and Magnetic Materials, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/86be32974f33c6d611eeec250acce93f685c6eca