MoO3 Electrochromic Layer Deposited by Chemical Vapor Transport of Volatile MoO3(OH)2

Abstract

MoO3 has an attention in the industrial application fi elds of photochromic, electrochromic, sensor and catalyst. Among them, MoO3 thin fi lms have been extensively investigated in the electrochromic (EC) device field due to its superior optical properties. Recently, many deposition techniques have been developed including chemical vapor deposition (CVD), evaporation, sol-gel coating, sputtering, and pulsed laser deposition (PLD). In this study, Mo oxide thin films was deposited by the chemical vapor transport (CVT) of MoO3(OH)2 during reduction of MoO3 powder in H2 and MoO3 thin films was subsequently obtained through the thermal annealing at O2. As annealing commenced, optical transmittance of the films increased due to enhancement of the crystallinity resulted from oxygen vacancy reduction and increase of the relative density from reduction of porosity. Also, the annealed MoO3 thin film was intercalated by ions in LiClO4+propylene carbonate (PC) solution as electrolyte and electrochromic property was analyzed.