采用射频磁控溅射制备了具有特殊层状纳米结构的碲化铋热电薄膜.以Bi2Te3为靶材,在不同基底温度和沉积时间下制备了薄膜,并利用x射线衍射、扫描电镜和x射线能谱等对样品进行了结构和成分分析,同时测试了薄膜的电导率和Seebeck系数.结果表明,基底温度是影响薄膜微结构和热电性能的关键因素之一,较高的基底温度利于层状结构的形成和功率因子的提高,400℃基底温度下制备薄膜的功率因子最优.然而,所有薄膜均显示不同程度偏离Bi:Te3的化学计量比而缺Te,优化薄膜成分有望进一步提高薄膜的热电性能.
Bismuth tellaride thin films with layered nanostructure have been fabricated by radio frequency (RF) magnetron 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 microstructure and transport property of bismuth telluride thin films. High temperature is beneficial for the formation of layered nanostructure and the enhancement of power factor. The highest power factor was obtained on the thin film deposited 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.