Lead-Free Tin-Based Perovskite Solar Cells: Strategies Toward High Performance

Perovskite solar cells (PSCs) have achieved state-of-the-art efficiency, approaching monocrystalline silicon solar cells due to the superior optoelectronic properties and intensive research efforts, fulfilling its forthcoming commercial use at affordable costs. Nevertheless, the toxicity of lead (Pb) is still one of the obstacles hindering future large-scale production. Herein, the recent progress of emerging lead-free tin (Sn)-based PSCs is reviewed. First, the structural and photovoltaic-related properties of Sn-based perovskites are summarized. Following a brief introduction of film deposition methods, strategies recently adopted to obtain high performance are then discussed in detail. Finally, the current challenges and prospective opportunities are provided to help the further progression of Sn-based PSCs.