Preventing inhomogeneous elemental distribution and phase segregation in mixed Pb-Sn inorganic perovskites via incorporating PbS quantum dots

Inhomogeneous Pb/Sn elemental distribution and the resulted phase segregation in mixed Pb-Sn halide perovskites would result in energy disorder (band structure and phase distribution disorder), which greatly limits their photovoltaic performance. Here, PbS quantum dot has been synthesized and demonstrated as seeds for modulation crystallization dynamics of the mixed Pb-Sn inorganic perovskites, allowing an enhanced film quality and significantly suppressing phase segregation. With this additive power conversion efficiency of 8% and 6% is obtained under irradiation of full sunlight in planar and mesoporous structured solar cells in combination with CsPb0.5Sn0.5I2Br inorganic perovskite, respectively. Our finding reveals exploring the actual Pb/Sn atoms location in perovskite structure and its influence on developing efficient and stable low-bandgap perovskite solar cells. (C) 2021 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

The inhomogeneous Pb/Sn elemental distribution and phase segregation in mixed Pb-Sn halide perovskites limit their photovoltaic performance. By using PbS quantum dots for modulation of crystallization dynamics, film quality can be improved and phase segregation can be suppressed, resulting in enhanced efficiency of solar cells.