Electrochromism of Reactive Magnetron Sputtered Tungsten Oxide Thin Films

반응성 마그네트론 스퍼터링법에 의해 증착된 $WO_3$ 박막의 일렉트로크로믹 특성

Tungsten oxide($WO_3$) thin films were prepared by reactive magnetron sputtering in an $Ar/O_2$ atmosphere from a compressed powder $WO_3$ target and their electrochromic(EC) phenomena were investigated. PEO-$LiClO_4$-PC polymer electrolyte can easely be formed into thin films and showed high transmittance. Such electrolyte have electrochromic properties suitable for large-scale electrochromic devices. For the devices using $WO_3$ thin films of 1500, 2500, $4000{\AA}$ thickness with glass/ITO/$WO_3$/PEO-$LiClO_4$-PC/ITO/glass structure, an optical modulation of $50{\sim}60%$ were obtained at a potential range of $1{\sim}2V$. It has shown that transmittance and reflectance of light could be electrically controlled by low applied voltage.