Nickel Oxide (NiOx) Hole Transport Layers in Perovskite Solar Cells: Doping Strategies, Interface Engineering, and Device Performance
Perovskite solar cells (PSCs) have demonstrated remarkable progress, achieving power conversion efficiencies exceeding 25% within a decade. Their further advancements critically depend on the stability and efficiency of the hole transport layer (HTM). Although organic HTMs such as spiro‐OMeTAD have dominated early PS...