The Role of Au in the Thermoelectric Properties of Amorphous Ge/Au and Si/Au Thin Films

Amorphous Si-Ge-Au thin films exhibit high thermoelectric power. To understand the role of Au in the thermoelectric properties, we studied the structural and thermoelectric properties of Si/Au and Ge/Au thin films. Samples were prepared by electron beam evaporation. Au was found to have two important roles. One is as a carrier source. Therefore, Au composition influences thermoelectric properties. The other role is that Au causes the crystallization of Si and Ge at lower temperature. The grain size ranged from ten to a few tens of nanometers. We conclude that the fine structure is important for high thermoelectric performance.