Advances in inverted perovskite solar cells

Considerable efforts are being made to advance inverted (p–i–n) perovskite solar cells (PSCs). Several passivation and insulation strategies have effectively been applied to reduce non-radiative recombination, a notorious issue for PSCs. Consequently, the performance of inverted PSCs has begun to rival those of regular (n–i–p) PSCs, with power conversion efficiency (PCE) values above 26%. The efficiency of tandem solar cells containing an inverted PSC as a subcell has also grown rapidly, reaching >33%. This Review discusses the origin of non-radiative recombinations in PSCs and recent progress in reducing them. We review how innovative device configurations, perovskite composition and interfacial engineering contribute to the high efficiency and long-term operational stability of inverted PSCs. We aim to provide readers with important insights into materials chemistry, physical processing and device configurations to further improve perovskite-based photovoltaics.