O-vacancy driven structural tuning and enhanced polaron transport in metal/amorphous MoO3 interfaces

In this study, we investigate metal–interface-driven O-vacancy formation within the amorphous molybdenum trioxide (a-MoO3) lattice, in multilayer heterostructures comprising alternating metal (Au or Ti) and a-MoO3 thin films. X-ray and Raman spectroscopies reveal a preferential depletion of O1 sites, leading to a Mo5+ concentration that scales with the metal reactivity. Combining structural and electronic transport analyses, we demonstrate the tunability of the polaronic hopping mechanism via O-vacancies, as well as their role in local structural distortions and consequent modulation of bonding stiffness. Our results establish multi-metal/oxide interface architectures as effective catalysts for oxygen-vacancy engineering in amorphous oxides, enabling tunable electronic functionality in disordered systems.