Advancements in the stability, protection and lead-free strategies of perovskite solar cells: a critical review

Lead toxicity is a challenge for the large-scale commercial production and the field implementation of photovoltaics. The fabrication of lead-free perovskite solar cells (PSCs) is environmentally acceptable; researchers have investigated the unique perovskite materials that are non-toxic in nature. The recent advancements in PSCs with suitable bandgap energy, optical and electrical features and structural alterations, methods for manufacturing metal electrodes and their internal and external effects have been investigated. Moreover, the toxic lead causes various diseases due to lead spreading in the environment which has been minimized by encapsulation. Incorporation of heterovalent and isovalent materials to reduce lead toxicity and improve stability has been discussed, and encapsulation techniques to avoid deterioration and corrosion have also been discussed. This critical review addresses the stability issues and challenges of PSCs. The intention is to pique the interest of younger researchers already active in this rapidly emerging study area.