Earth-abundant non-toxic perovskite nanocrystals for solution processed solar cells
In this review, we summarize some of the non-toxic alternatives that have been synthesized as nanocrystals and incorporated in photovoltaic solar cells, specifically: tin (Sn), germanium (Ge), bismuth (Bi), and antimony (Sb)-based materials. Our findings show that this field has been scarcely covered; there are very few reports on non-toxic perovskite nanocrystals incorporated in solar cells and in general, the efficiencies are still modest. However, this area deserves more attention since some nanocrystal-based solar cells already outperform bulk counterparts. For each case, we also discuss factors limiting efficiency, the approaches followed to overcome these limitations, and the possible solutions to improve efficiency.