Organic-inorganic hybrid perovskite materials has become one of the hot topics in the field of photovoltaic research due to its high performance and low cost. In the current study, perovskite solar cells with high conversion efficiency mostly contain Pb element, especially those materials based on CH3NH3PbI3. There is, therefore, a strong desire to replace the toxic lead with a non-toxic element that does not dramatically affect its conversion efficiency. In our research, the decomposition enthalpy, band structures and optical properties of Cs4IV(1)IV(2)2I12 have been studied according to first-principles density functional theory. Stability is shown by calculation of decomposition energy: Cs4PbSn2I12&gt;Cs4SnSn2I12&gt;Cs4SnPb2I12&gt;Cs4PbPb2I12. In addition, from the optical properties of Cs4SnSn2I12, there is a peak in the initial stage of optical absorption, indicating that it has the properties of two-dimensional materials. Therefore, Cs4SnSn2I12 is more stable than CsSnI3 and has sharp absorption coefficient (~105 cm-1). It could be concluded that doping Sn4+ is more conducive to the stability of perovskite structure than Sn2+. The Sn-based perovskite is a good candidate material for solar cells, and it also provides a direction for the research of lead-free perovskite solar cells.

Vacancy-driven stabilization of tin-based perovskite solar cell absorber materials

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.