The importance of elemental lead to perovskites photovoltaics

Perovskite photovoltaic has been attracting intense attention as an emerging technology due to its figure of merits including high power conversion efficiency, low-cost fabrication, and others. A successful commercialization of this type of technology has been significantly retarded by issues of elemental toxicity and device stability which are related to the key component of lead (Pb) in most efficient halide perovskites. Here, we first elucidated the origin of the superior optoelectronic properties of lead halide perovskites and their impact on photovoltaic device performance. We then discussed the promising approaches to solve the toxicity issue of lead hybrid perovskites. We further outlooked the effective solutions for lead hybrid perovskites for solar cell application. This review may provide a guidance for researchers interested in facilitating perovskite solar cells from exploitation to application.