Importance of Reducing Vapor Atmosphere in the Fabrication of Tin-Based Perovskite Solar Cells

作者：Song, Tze-Bin; Yokoyama, Takamichi; Stoumpos, Constantinos C.; Logsdon, Jenna; Cao, Duyen H.; Wasielewski, Michael R.; Aramaki, Shinji; Kanatzidis, Mercouri G.^*

来源：Journal of the American Chemical Society, 2017, 139(2): 836-842.

DOI：10.1021/jacs.6b10734

• FREE HALIDE PEROVSKITE
• PHASE-TRANSITIONS
• HIGH-EFFICIENCY
• SEMICONDUCTORS
• PERFORMANCE
• PHOTOLUMINESCENCE
• MOBILITIES
• CIRCUIT
• COMPLEX
• DESIGN

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 MASnI(3), 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 MASnI(3), 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 Sri-based halide perovskite materials, paving the way to the realization of low-cost and lead-free Sn-based halide perovskite solar cells.

• 出版日期2017-1-18
• 单位西北大学