| AVS 62nd International Symposium & Exhibition | |
| Electronic Materials and Processing | Tuesday Sessions |
| Session EM-TuP |
| Session: | Electronic Materials and Processing Poster Session |
| Presenter: | Jenna Walrath, University of Michigan |
| Authors: | J.C. Walrath, University of Michigan A.S. Chang, University of Michigan V.A. Stoica, University of Michigan Y.H. Lin, University of Michigan W. Liu, University of Michigan L. Endicott, University of Michigan C. Uher, University of Michigan R. Clarke, University of Michigan R.S. Goldman, University of Michigan, Ann Arbor |
| Correspondent: | Click to Email |
Bi2Te3 and Sb2Te3 are well-known materials for thermoelectric applications, which have also recently been identified as topological insulators (Tis) with surface states consisting of a single Dirac cone. Spin-momentum locking in Tis make them desirable for spintronics and other applications. However, to be useful for such devices, these materials must be bulk insulating and have accessible surface states, requiring both the Fermi level and the Dirac point to be located within the bulk bandgap. Furthermore, it is desirable to possess these properties at room temperature in ambient conditions. Robust surface states in ambient conditions have been demonstrated for Bi2Se3, [1] but to our knowledge direct detection of topological surface states has yet to be demonstrated in BiSbTe systems. Here we use scanning tunneling microscopy and spectroscopy to characterize the band structure of 30nm MBE-grown (Bi.42Sb.58)2Te3 thin films, revealing the presence of topological surface states within the bulk band gap. Both the Fermi level and the Dirac point are located inside the bulk bandgap, indicating bulk insulating behavior with accessible surface states. Furthermore, the surface states are robust to room temperature and limited air exposure.
[1] C. Chen, S. He, H. Weng, W. Zhang, L. Zhao, H. Liu, X. Jia, D. Mou, S. Liu, J. He, Y. Peng, Y. Feng, Z. Xie, G. Liu, X. Dong, J. Zhang, X. Wang, Q. Peng, Z. Wang, S. Zhang, F. Yang, C. Chen, Z. Xu, X. Dai, Z. Fang, and X.J. Zhou, Proc. Natl. Acad. Sci. U.S.A.109, 3694 (2012).