1 research outputs found
Importance of Reducing Vapor Atmosphere in the Fabrication of Tin-Based Perovskite Solar Cells
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 Sn<sup>4+</sup> 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<sub>3</sub>, CsSnI<sub>3</sub>, and
CsSnBr<sub>3</sub> 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<sub>3</sub>, CsSnI<sub>3</sub>, and CsSnBr<sub>3</sub>, respectively. The reducing vapor atmosphere process results
in more than 20% reduction of Sn<sup>4+</sup>/Sn<sup>2+</sup> 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