Lead-Free Metal Halide Perovskites for Solar Cell Applications: A Theoretical Perspective

In recent years, significant efforts have been paid to develop Pb-free halide perovskite and perovskite derivative absorber materials for solar cell applications. However, so far, solar cells based on these materials showed significantly inferior performances as compared to their Pb halide perovskite counterparts. Here, we provide a theoretical perspective on lead-free metal halide perovskites and derivatives for solar cell applications. We first show a theoretical understanding of the origins of the superior photovoltaic properties of Pb halide perovskites. We then show that Pb-replacing leads to reduced structural and electronic dimensionality, degrading the superior photovoltaic properties in Pb-free metal halide perovskites and perovskite derivatives.