PHOTO- AND ELECTROCHROMIC PROPERTIES OF ACTIVATED REACTIVE EVAPORATED MOO3 THIN FILMS GROWN ON FLEXIBLE SUBSTRATES

Abstract

The molybdenum trioxide () thin films were grown onto ITO-coated flexible Kapton substrates using plasma assisted activated reactive evaporation technique. The film depositions were carried out at constant glow power and oxygen partial pressures of 8 W and Torr, respectively. The influence of substrate temperature on the microstructural and optical properties was investigated. The thin films prepared at a substrate temperature of 523 K were found to be composed of uniformly distributed nanosized grains with an orthorhombic structure of -. These nanocrystalline thin films exhibited higher optical transmittance of about 80% in the visible region with an evaluated optical band gap of 3.29 eV. With the insertion of 12.5 mC/, the films exhibited an optical modulation of 40% in the visible region with coloration efficiency of 22 /C at the wavelength of 550 nm. The films deposited at 523 K demonstrated better photochromic properties and showed highest color center concentration for the irradiation time of 30 minutes at 100 mW/.