Tuning thermoelectricity in a Bi2Se3 topological insulator via varied film thickness

• Published in: New Journal of Physics
• Main Authors: Minghua Guo, Zhenyu Wang, Yong Xu, Huaqing Huang, Yunyi Zang, Chang Liu, Wenhui Duan, Zhongxue Gan, Shou-Cheng Zhang, Ke He, Xucun Ma, Qikun Xue, Yayu Wang
• Format: Article
• Language: English
• Published: IOP Publishing 2016-01-01
• Subjects: topological insulator; thermoelectricity; transport; Seebeck coefficient
• Online Access: https://doi.org/10.1088/1367-2630/18/1/015008
• ISSN: 1367-2630

We report thermoelectric transport studies on Bi _2 Se _3 topological insulator thin films with varied thickness grown by molecular beam epitaxy. We find that the Seebeck coefficient and thermoelectric power factor decrease systematically with the reduction of film thickness. These experimental observations can be explained quantitatively by theoretical calculations based on realistic electronic band structure of the Bi _2 Se _3 thin films. This work illustrates the crucial role played by the topological surface states on the thermoelectric transport of topological insulators, and sheds new light on further improvement of their thermoelectric performance.