Tin‐Based Eco‐Friendly Perovskites for Sustainable Future

Perovskite solar cells (PSCs) have opened a floodgate of diverse research. These highly functional materials have immense potential prospects in renewable energy, optoelectronic applications, to name a few. Most of the perovskites have lead (Pb) as an integral active component. Though the Pb‐based organometallic perovskites have shown outstanding performance (over 25%), significant challenges exist including the presence of Pb, its toxicity as well as the instability that can hamper the use of these devices toward practical applications. There are some instances where a complete absence of Pb has been used to achieve respectable device performance, but they face a challenge from the towering success of their counterparts. To offset the issues, significant efforts are being carried out to employ other alternatives (cations) in conjunction with Pb, without distorting the inherent material properties. To that end, tin (Sn) has emerged as a promising alternative to Pb in achieving benchmark performance. Bringing these Sn PSCs into more prominence is a crucial step in taking low Pb or Pb‐free PSCs to the next level of research and commercialization. In this topical review, the notable advancements are highlighted, overviewed and recommendations are made for prospects toward environmentally friendly Sn‐based perovskite photovoltaics.