Recent progress of inorganic perovskite solar cells
The power conversion efficiency of organic–inorganic hybrid perovskite solar cells (PSCs) has been boosted to be comparable with that of commercial silicon solar cells. Although the fabrication cost of solution-processing PSCs can be lower than that of silicon solar cells, PSCs are still facing the big challenge of instability in air due to the presence of organic components in the perovskites. To obtain stable PSCs, fully replacing the A-site organic cations with pure inorganic cations is one of the promising methods. To date, many researchers have studied the inorganic PSCs with astonishing breakthroughs, and the PCE of inorganic lead-based PSCs has exceeded 17%. In this review, the recent progress of inorganic PSCs is summarized and discussed for different perovskite compositions. The challenges of inorganic PSCs are revealed, followed by the outlook of this field.