1. Formation of Stable Tin Perovskites Co-crystallized with Three Halides for Carbon-Based Mesoscopic Lead-Free Perovskite Solar Cells.
- Author
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Tsai, Cheng‐Min, Mohanta, Nayantara, Wang, Chi‐Yung, Lin, Yu‐Pei, Yang, Yaw‐Wen, Wang, Chien‐Lung, Hung, Chen‐Hsiung, and Diau, Eric Wei‐Guang
- Subjects
TIN compounds ,PEROVSKITE ,CRYSTALLIZATION ,SOLAR cells ,MESOSCOPIC systems ,HALIDES ,CARBON compounds - Abstract
We synthesized and characterized methylammonium (MA) mixed tri-halide tin perovskites (MASnIBr
2− x Clx ) for carbon-based mesoscopic solar cells free of lead and hole-transporting layers. Varied SnCl2 /SnBr2 ratios yielded tin perovskites with three halides (I, Br, and Cl) co-crystallized inside the tin-perovskite. When the SnCl2 proportion was ≥50 % ( x≥1), phase separation occurred to give MASnI3− y Bry and MASnCl3− z Brz in the stoichiometric proportions of their precursors, confirmed by XRD. A device with MASnIBr1.8 Cl0.2 (SnCl2 =10 %) showed the best photovoltaic performance: JSC =14.0 mA cm−2 , VOC =380 mV, FF=0.573, and PCE=3.1 %, and long-term stability. Electrochemical impedance spectra (EIS) show superior charge recombination and dielectric relaxation properties for the MASnIBr1.8 Cl0.2 cell. Transient PL decays showed the intrinsic problem of tin-based perovskites with average lifetimes less than 100 ps. [ABSTRACT FROM AUTHOR]- Published
- 2017
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