Abstract
Tin-based halide perovskite materials have been successfully employed in lead-free perovskite solar cells, but the tendency of these materials to form leakage pathways from p-type defect states, mainly Sn4+ and Sn vacancies, causes poor device reproducibility and limits the overall power conversion efficiencies (PCEs). Here, we present an effective process that involves a reducing vapor atmosphere during the preparation of Sn-based halide perovskite solar cells to solve this problem, using MASnI3, CsSnI3, and CsSnBr3 as the representative absorbers. This process enables the fabrication of remarkably improved solar cells with PCEs of 3.89%, 1.83%, and 3.04% for MASnI3, CsSnI3, and CsSnBr3, respectively. The reducing vapor atmosphere process results in more than 20% reduction of Sn4+/Sn2+ ratios, which leads to greatly suppressed carrier recombination, to a level comparable to their lead-based counterparts. These results mark an important step toward a deeper understanding of the intrinsic Sn-based halide perovskite materials, paving the way to the realization of low-cost and lead-free Sn-based halide perovskite solar cells.
Original language | English (US) |
---|---|
Pages (from-to) | 836-842 |
Number of pages | 7 |
Journal | Journal of the American Chemical Society |
Volume | 139 |
Issue number | 2 |
DOIs | |
State | Published - Jan 18 2017 |
Funding
T.-B.S. acknowledges financial support from Mitsubishi Chemical Group Science & Technology Research Center, Inc. D.H.C. acknowledges support from the Link Foundation through the Link Foundation Energy Fellowship Program. This work was supported in part by the ANSER Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Award No. DE-SC0001059 (solar absorber material synthesis and solar cell characterization). This work made use of the EPIC facility (NUANCE Center-Northwestern University), which has received support from the MRSEC program (NSF DMR-1121262) at the Materials Research Center, and the Nanoscale Science and Engineering Center (EEC-0118025/003), both programs of the National Science Foundation; the State of Illinois; and Northwestern University.
ASJC Scopus subject areas
- Catalysis
- General Chemistry
- Biochemistry
- Colloid and Surface Chemistry