[20p-C310-1~16] 6.4 Thin films and New materials

△ [20p-C310-6] Electrochromic properties of Mg doped IrO₂ films deposited by co-sputtering

〇Yuna Suga¹, Makoto Kashiwagi¹, JunJun Jia², Shin-ichi Nakamura³, Yuzo Shigesato¹ (1.Aoyama Gakuin Univ., 2.Waseda Univ., 3.Center for Instrumental Analysis,Aoyama Gakuin Univ.)

Keywords:Iridium oxide, Electrochromism, Co-sputtering

IrO₂ is an anodic electrochromic (EC) material, i.e. colored by electrochemical oxidation. It is colored or bleached by changing the valence of Ir between Ir (Ⅲ) and Ir (Ⅳ). IrO₂ has been expected to be used for the counter electrode against the excellent cathodic a-WO₃ films. However, IrO₂ performs much lower coloration efficiency and smaller capacity than the a-WO₃ films. Moreover, Ir is very rare and expensive metal. Therefore, mixed oxide should be effective to reduce the amount of Ir. In this study, Mg doped IrO₂ films were deposited by rf reactive co-sputtering under various conditions. Mg doped IrO₂ films showed larger capacitance and higher coloration efficiency when [Ir / (Ir + Mg)] was about 20 at%. For the comparative purpose, Mg doped NiO films, one of the another famous anodic materials, were also deposited on unheated ITO coated glasses by rf reactive sputtering under various conditions.