[16p-2D-1~14] 13.1 Fundamental properties, surface and interface, and simulations of Si related materials

[16p-2D-5] Flattening of Ge Surfaces by Catalytic Metals to Enhance O₂ Reduction Reactions in Water

〇Kenta Arima¹, Tatsuya Kawase¹, Yusuke Saito¹, Kentaro Kawai¹, Yasuhisa Sano¹, Kazuto Yamauchi¹, Mizuho Morita¹ (1.Osaka Univ.)

Keywords:germanium surface,oxygen reduction reaction,water

We demonstrated surface flattening of Ge by metal-assisted chemical etching mediated by dissolved-oxygen molecules in water. Namely, we formed a Pt thin film on a soft elastomer pad, which was in contact with a Ge wafer in O₂-saturated water. After both the catalyst plate and the Ge wafer were rotated in the same plane, we have found that the surface microroughness of Ge was improved. It is probably owing to the preferential contact of surface protrusions of Ge with a Pt surface. This was followed by the oxidation of these protrusions by the catalytic activity of Pt to enhance the O₂ reduction reaction in water. Because the surface protrusions composed of GeO₂ were dissolved, the flattened Ge surface was obtained.