Molybdenum oxide (MoO 3 ) thin film based electrochromic cell characterisation in 0·1M LiClO 4 .PC electrolyte

Abstract

Electrochromic thin films of molybdenum oxide (MoO₃) were prepared on transparent conducting oxide substrates, i.e. fluorine doped tin oxide coated (FTO or SnO₂:F) glass substrates by electron beam evaporation technique using pure MoO₃ (99.99%) pellets at various substrate temperatures (i.e. T_sub=room temperature (30°C), 100 and 200°C) under the vacuum of 1 × 10⁻⁵ mbar. The room temperature prepared films were further annealed T_anne at 200 and 300°C for about one hour in the vacuum environment. The electrochemical nature of the films was studied by the cyclic voltammetry technique using a three electrode electrochemical cell in 0·1M LiClO₄.PC electrolyte. The performance of the films was also tested by making electrochromic cells. The films produced at higher substrate temperature show lesser modulation in the visible spectrum, compared with the films produced at lower temperatures. A maximum colouration efficiency of 66 cm² C⁻¹ was observed in the infrared region for the films prepared at room temperature.