Structural and optical properties of $TiO_2$ thin film fabricated by reactive sputtering

반응성 스퍼터링법으로 제조된 $TiO_2$ 박막의 구조적 및 광학적 특성

$TiO_2$ is a wide band-gap semiconductor (3.4 eV) and can only absorb about 5% of sun light. in the ultraviolet light region, which largely limits its practical applications because of the lower utility of sun light and quantum yield. In order to move the absorption edge of $TiO_2$ films to visible spectrum range, we have made the impurity level within a band-gap of $TiO_2$ thin film by introduction of oxygen vacancy. Oxygen-defected $TiO_2$ thin film have prepared by reactive sputtering with the partial pressure of Ar:$O_2$=10:90~99.33:0.66 ratio. As a result, we could have the impurity level of about 2.75 eV on condition that oxygen partial pressure is below 7%.