85 °C/85%‐Stable n‐i‐p Perovskite Photovoltaics with NiO<i>_x</i> Hole Transport Layers Promoted By Perovskite Quantum Dots

Abstract

Abstract Power conversion efficiency (PCE) and long‐term stability are two vital issues for perovskite solar cells (PSCs). However, there is still a lack of suitable hole transport layers (HTLs) to endow PSCs with both high efficiency and stability. Here, NiO x nanoparticles are promoted as an efficient and 85 °C/85%‐stable inorganic HTL for high‐performance n‐i‐p PSCs, with the introduction of perovskite quantum dots (QDs) between perovskite and NiO x as systematic interfacial engineering. The QD intercalation enhances film morphology and assembly regulation of NiO x HTLs . Due to structure–function correlations, hole mobility within NiO x HTL is improved. And the hole extraction from perovskite to NiO x is also facilitated, resulting from reduced trap states and optimized energy level alignments. Hence, the promoted NiO x ‐based n‐i‐p PSCs exhibit high PCE (21.59%) and excellent stability (sustaining 85 °C aging in air without encapsulation). Furthermore, encapsulated solar modules with QDs‐promoted NiO x HTLs show impressive stability during 85 °C/85% aging test for 1000 hours. With high transparency, QDs‐promoted NiO x is also demonstrated to be an advanced HTL for semitransparent PSCs. This work develops promising NiO x inorganic HTL in n‐i‐p PSCs for manufacturing next‐generation photovoltaic devices.