Organic-inorganic hybrid electron transport layer of PVP-doped SnO2 for high-efficiency stable perovskite solar cells

SnO2 is one of the most popular low-cost inorganic electron transport materials for perovskite solar cells. However, the agglomeration of SnO2 nanoparticles causes their uneven distribution and the existence of pin-holes, seriously hindering the electron migration across SnO2/perovskite interface and limiting the device per-formance. The poor wettability between the SnO2 film and the perovskite precursor solution also impairs the growth of perovskite grains. In this work, an innovative strategy was employed to produce an organic-inorganic hybrid electron transport layer (ETL) by fabricating a high-quality polyvinylpyrrolidone (PVP)/SnO2 perovskite film with few defects and good wettability. In turn, a PVP-SnO2 based device exhibits elevated power conversion efficiency (PCE) (18.98%) and adequate reproducibility along with superior operational stability.