Study on structural and optical properties of thermally evaporated MoO3 thin films

Molybdenum trioxide (MoO3) thin films are grown on ITO-coated glass substrates by thermal deposition technique under the presence of oxygen partial pressure (PO2) about 2 × 10–3 mbar at various substrate temperatures to enhance electrochromic efficiency. Even at room temperature, the experimental films were crystalline, and crystallinity increased as the substrate temperature (Ts) was raised to 150°C. It is noted that the uniform spherical structure was transformed to a needle-like structure at Ts = 150°C. The transmittance of the films improved with substrate temperature, and corresponding bandgap values were measured. The films grown at Ts = 150°C reported the highest colouration efficiency.