Use of Hydrogen Molybdenum Bronze in Vacuum‐Deposited Perovskite Solar Cells

Herein, the dehydration of a hydrogen molybdenum bronze (HYMoO3), converting it to molybdenum oxide (MoOX), is explored toward the development of perovskite solar cells (PSCs) for the first time. H0.11MoO3 bronze is synthesized, characterized, and deposited on indium tin oxide (ITO) under different concentrations and annealing conditions for in situ conversion into MoOX with appropriate oxygen vacancies. Vacuum‐deposited PSCs are fabricated using the as‐produced MoOX hole injection layers, achieving a power conversion efficiency of 17.3% (average) for the optimal device. The latter has its stability and reproducibility tested, proving the robustness and affordability of the developed hole transport layer in PSCs. Herein, hydrogen molybdenum bronze (H0.11MoO3) is in situ converted to molybdenum oxide (MoO2.94) on top of indium tin oxide (ITO) and explored as a hole transport layer in vacuum‐deposited perovskite solar cells. A power conversion efficiency of 17.3% (average) is achieved for an ITO/MoO2.94/TaTm/CH3NH3PbI3/C60/BCP/Ag optimal device, with great stability and reproducibility.