Ternary oxide BaSnO3 nanoparticles as an efficient electron-transporting layer for planar perovskite solar cells

Organic-inorganic hybrid perovskites are a promising candidate for fabricating high-efficiency solar cells. In this work, well-dispersed ternary oxide BaSnO 3 (BSO) nanoparticles with high crystallinity were successfully synthesized by a facile peroxide-precipitate route. And then BSO was first used as an efficient electron-transporting layer in planar perovskite solar cells . Influences of the coverage, roughness and thickness of planar BSO layer on the photovoltaic performance of the solar cells were systemically investigated. It is found that better coverage of BSO layer on the transparent oxide electrodes can significant reduce current leakage and suitable thickness of electron-transporting layer is favorable to reduce series resistance. Both of them contribute to the improved power conversion efficiency of cell devices. Additionally, the BSO-based device exhibits a comparable device performances to the TiO 2 one, which can be ascribed to the efficient charge extraction as BSO/perovskite interfaces, the low charge transfer resistance and the suppressed carrier recombination. The optimized BSO-based planar perovskite solar cells exhibits power conversion efficiency of 10.96% with J sc of 17.45 mA/cm 2 , V oc of 0.986 V and FF of 0.637. Thus, this work will pave the way for employing ternary oxide as electron-transporting material for high-performance perovskite solar cells.