Structure and phase dynamics in electrospray deposited amorphous MoO3 via thermal treatment

Molybdenum oxides with distinct structures and phases have shown unique properties that are of interest in many scientific and technological applications. However, the scalability to large area deposition and in particular the deposition of surfaces with specific topology, with a uniform and controlled structure still remains a challenge. In this work, a uniform MoO3 film with amorphous structure was achieved via electrospray deposition from fine particle dispersion in water. A high vapor pressure solvent was utilized for the progress of the deposition. As-deposited films with large thicknesses ( < 1 μ m) show amorphous structures with a mean roughness lower than ∼32 nm. The deposited film was subsequently subject to thermal treatment with optimal thermodynamic parameters in order to modify the structure, the phase, the defect density and subsequently the electronic properties of the final structure. It is shown that a uniform coating layer with controlled structure and defect density can be achieved. This method facilitates the deposition of oxide layers on a variety of unconventional surfaces with large area as well as curved geometry.