Recent advances in tin halide perovskite solar cells: a critical review

Abstract

Tin (Sn) halide-based perovskites are rising as competitive candidates for eco-friendly perovskite solar cells (PSCs) that have garnered immense attention. In particular, the power conversion efficiency (PCE) of the Sn-based perovskite solar cells (TPSCs) has exceeded 17%, ranking above all the other lead-free perovskite photovoltaics. Nevertheless, the problems of intrinsic instability and extremely fast crystallization of TPSCs place restrictions on both the device performance and stability, hampering their commercial applications. Fortunately, valid strategies have been developed and extensively studied over the past few years, and the fundamental problems of Sn-based perovskites have been effectively addressed, taking a big step forward in the field of TPSCs. In this review, initially, an overview is given on the unique properties of Sn-based perovskite materials, encompassing their crystallographic structures, optoelectronic characteristics, and chemical degradation pathways. Furthermore, the state-of-the-art strategies, including structural engineering, crystallization regulation and interface engineering, toward high-performance TPSCs are comprehensively reviewed. Finally, we present future challenges faced by Sn-based perovskites and provide crucial perspectives for further realizing efficient and stable TPSCs, thereby laying the critical foundation for future practical applications of Sn-based perovskites not only in PSCs but also in many other thin-film optoelectronic devices.