Growth and Transport Properties of Layered Bismuth Telluride Thin Films via Radio Frequency Magnetron Sputtering

Bismuth telluride thin films with layered nanostructure have been fabricated by radio frequency (RF) mag- netron sputtering. Thin films were deposited at various substrate temperatures and durations with a single Bi2Te3 target. The microstructures and chemical compositions of these films were characterized by X-ray diffraction (XRD), scan- ning electron microscope (SEM) and energy dispersive spectroscope (EDS). Electrical transport property and Seebeck coefficient were measured on these thin films. The results show that substrate temperature is a key factor on the micro- structure and transport property of bismuth telluride thin films. High temperature is beneficial for the formation of lay- ered nanostructure and the enhancement of power factor. The highest power factor was obtained on the thin film de- posited at 400℃. However, Te deficiency was observed in these thin films. Thus thermoelectric property would be further enhanced by optimizing composition of these thin films.