Fabrication of high-quality Mo-doped BiVO 4 thin films with linearly controlled oxygen vacancy content

Abstract BiVO 4 (BVO), a photocatalytic material with broad application prospects, faces practical limitations due to high photogenerated carrier recombination rates and poor charge mobility. Oxygen vacancies play a crucial role in regulating the photocatalytic performance of BiVO 4 . Elemental doping can modulate oxygen vacancy concentration, but establishing a precise, quantitative relationship between dopant concentration and oxygen vacancy formation remains a challenge. To address these challenges, this study employed magnetron sputtering technology to establish a relatively ideal single-crystal thin-film system that minimizes interference from complex factors. Within this system, controlled Mo doping was implemented to precisely regulate the oxygen vacancy concentration. The focus is on investigating the impact of Mo doping on BVO’s physical properties. Characterization confirmed that the monoclinic crystal structure, epitaxial growth pattern, and surface morphology of Mo-doped BVO films remain unchanged, achieving stable Mo doping while preserving BVO lattice integrity. Detailed characterization demonstrated that the oxygen vacancy concentration could be linearly and precisely modulated by varying the Mo doping level, thereby establishing a quantitative relationship between doping and vacancy formation.