Topological Surface State Enhanced Photothermoelectric Effect in Bi2Se3 Nanoribbons

• Published in: Nano letters 2014-08, Vol.14 (8), p.4389-4394
• Main Authors: Yan, Yuan, Liao, Zhi-Min, Ke, Xiaoxing, Van Tendeloo, Gustaaf, Wang, Qinsheng, Sun, Dong, Yao, Wei, Zhou, Shuyun, Zhang, Liang, Wu, Han-Chun, Yu, Da-Peng
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic structure of nanoscale materials : clusters, nanoparticles, nanotubes, and nanocrystals; Exact sciences and technology; Materials science; Nanoscale materials and structures: fabrication and characterization; Nanotubes; Physics
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl501276e

The photothermoelectric effect in topological insulator Bi2Se3 nanoribbons is studied. The topological surface states are excited to be spin-polarized by circularly polarized light. Because the direction of the electron spin is locked to its momentum for the spin-helical surface states, the photothermoelectric effect is significantly enhanced as the oriented motions of the polarized spins are accelerated by the temperature gradient. The results are explained based on the microscopic mechanisms of a photon induced spin transition from the surface Dirac cone to the bulk conduction band. The as-reported enhanced photothermoelectric effect is expected to have potential applications in a spin-polarized power source.