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.