Photo- and Electrochromic Properties of Activated Reactive Evaporated MoO3 Thin Films Grown on Flexible Substrates

• Published in: Journal of nanotechnology 2008-01, Vol.2008
• Main Authors: Krishna, K Hari, Hussain, O M, Guillen, C
• Format: Article
• Language: English
• Subjects: Glass substrates; Grain growth; Molybdenum; Plasma; Studies; Temperature
• ISSN: 1687-9503; 1687-9511
• DOI: 10.1155/2008/217510

The molybdenum trioxide ([subscript]MoO3[/subscript] ) 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 1×[superscript]10-3[/superscript] Torr, respectively. The influence of substrate temperature on the microstructural and optical properties was investigated. The [subscript]MoO3[/subscript] 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 α-[subscript]MoO3[/subscript] . These nanocrystalline [subscript]MoO3[/subscript] 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/[superscript]cm2[/superscript] , the films exhibited an optical modulation of 40% in the visible region with coloration efficiency of 22 [superscript]cm2[/superscript] /C at the wavelength of 550 nm. The [subscript]MoO3[/subscript] 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/[superscript]cm2[/superscript] .