Nontoxic and Less Toxic Hybrid Perovskites: a Synergistic Strategy for Sustainable Photovoltaic Devices

• Published in: Solar RRL 2021-08, Vol.5 (8), p.n/a
• Main Authors: Attique, Sanam, Ali, Nasir, Rauf, Sajid, Ali, Shahid, Khesro, Amir, Khatoon, Rabia, Khan, Ehsan Ullah, Akram, Fazli, Yang, Shikuan, Wu, Huizhen
• Format: Article
• Language: English
• Subjects: lead-free perovskites; less toxic hybrid perovskites; nontoxic hybrid perovskites; organolead-halide perovskites; solar cells
• ISSN: 2367-198X; 2367-198X
• DOI: 10.1002/solr.202100212

A research hotspot for the last decade, organometal‐halide perovskites are now showing their promise in numerous optoelectronic devices. With power conversion efficiency (PCE) greater than 25%, perovskite solar cells (PSCs) are approaching the status of popular monocrystalline silicon–based solar cells (SCs). However, the presence of a bioaccumulative lead (Pb) in these perovskite compounds hinders their scalability and commercialization. The endeavor on nontoxic alternatives has triggered a new field of perovskites where Pb has been successfully eliminated. Preliminary studies of photovoltaic (PV) devices based on Pb‐free perovskites have shown some promise; however, they failed to exhibit comparable performance and compositional stability. Therefore, to exploit together the advantages of high efficiency and lesser toxicity, combinations of Pb alternatives with each other as well as with conventional Pb are required in the perovskite framework to fabricate hybrid perovskites (HPVKs). The first part of this Review briefly discusses all possible Pb substitutes and their limitations in PV devices. Based on the Pb contents, the second part elaborates on the two different types of HPVKs (i.e., nontoxic and less toxic) and their progress in photovoltaics. The Review concludes with an outlook discussing current challenges in the way of HPVKs and prospective opportunities to assess their future progress. Pb toxicity is a major hurdle in the commercialization of perovskite‐based photovoltaic devices. Numerous nontoxic Pb substitutes have been introduced; however, phase‐pure Pb‐free perovskite solar cells (PSCs) have failed due to poor performance and environmental stability. Therefore, hybrid perovskites (HPVKs) are inevitable for stable, efficient, and less‐toxic PSCs. HPVKs display better performance as well as environmental stability.