Abstract
Perovskite solar cells (PSCs) materials are progressing as potential candidates for the future generation of photovoltaics. Despite the most efficient photovoltaic performance, lead-based perovskite materials are not considered for commercialization due to the high toxicity of lead. One of the promising alternatives is tin (Sn)-based perovskites, which exhibits equivalent ionic size as lead and outstanding absorption properties. However, Sn-based perovskite materials have stability and low-performance issues because of the easy oxidation of Sn2+ to Sn4+and fast crystallization. This paper gives a focused overview of the notable recent studies to address the stability and low-performance challenges of Sn-based hybrid organic-inorganic perovskite (Sn-HOIP) materials for solar cells by using functional additives. To date, the addition of SnF2 additive in the methylammonium tin iodide-based PSCs has shown the highest efficiency of 7.78% and maintains 70% of original efficiency over 200-hours. In the case of formamidinium tin iodide-based PSCs, the addition of phenylhydrazine hydrochloride significantly increases the power conversion efficiency to 11.40% from 5.60% for a pristine device. However, further improvement in the stability and efficiency of Sn-based PSCs requires a molecular-level understanding of the role of existing and new candidates of additives tailored for evolving Sn-HOIP materials.
Tailoring capping-layer composition for improved stability of mixed-halide perovskites
