A Strategy to Produce High Efficiency, High Stability Perovskite Solar Cells Using Functionalized Ionic Liquid-Dopants.

Zhang, Yi; Fei, Zhaofu; Gao, Peng; Lee, Yonghui; Tirani, Farzaneh Fadaei; Scopelliti, Rosario; Feng, Yaqing; Dyson, Paul J et al. · Adv Mater · 2017

basic_science · Level V

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Abstract

Functionalized imidazolium iodide salts (ionic liquids) modified with CH<sub>2</sub> CHCH<sub>2</sub> , CH<sub>2</sub> CCH, or CH<sub>2</sub> CN groups are applied as dopants in the synthesis of CH<sub>3</sub> NH<sub>3</sub> PbI<sub>3</sub> -type perovskites together with a fumigation step. Notably, a solar cell device prepared from the perovskite film doped with the salt containing the CH<sub>2</sub> CHCH<sub>2</sub> side-chain has a power conversion efficiency of 19.21%, which is the highest efficiency reported for perovskite solar cells involving a fumigation step. However, doping with the imidazolium salts with the CH<sub>2</sub> CCH and CH<sub>2</sub> CN groups result in perovskite layers that lead to solar cell devices with similar or lower power conversion efficiencies than the dopant-free cell.