All-inorganic perovskite solar cells featuring mixed group IVA cations

All-inorganic perovskites are promising for solar cells owing to their potentially superior tolerance to environmental factors, as compared with their hybrid organic-inorganic counterparts. Over the past few years, all-inorganic perovskite solar cells (PSCs) have seen a dramatic improvement in certified power conversion efficiencies (PCEs), demonstrating their great potential for practical applications. Pb, Sn, and Ge are the most studied group IVA elements for perovskites. These group IVA cations share the same number of valence electrons and similarly exhibit the beneficial antibonding properties of lone-pair electrons when incorporated in the perovskite structure. Meanwhile, mixing these cations in all-inorganic perovskites provides opportunities for stabilizing the photoactive phase and tailoring the bandgap structure. In this mini-review, we analyze the structural and bandgap design principles for all-inorganic perovskites featuring mixed group IVA cations, discuss the updated progress in the corresponding PSCs, and finally provide perspectives on future research efforts faciliating the continued development of high-performance Pb-less and Pb-free all-inorganic PSCs.

Automated summary

The superior tolerance of all-inorganic perovskites compared to their hybrid counterparts makes them promising candidates for solar cells. In recent years, significant improvements have been achieved in certified power conversion efficiencies of all-inorganic perovskite solar cells (PSCs), highlighting their potential for practical applications. Group IVA elements, including Pb, Sn, and Ge, have been extensively studied for perovskites, and their incorporation into all-inorganic perovskite structures provides opportunities for stabilizing the photoactive phase and tailoring the bandgap structure. This review analyzes the design principles, discusses the progress in PSCs with mixed group IVA cations, and provides perspectives on future research efforts for high-performance Pb-less and Pb-free all-inorganic PSCs.