Thickness and Temperature Dependence of the Dielectric Function of Bi_{\mathrm{2}}Se_{\mathrm{3}}

Xiaoyu Wang; Frank Peiris; Maria Hilse; Roman Engel-Herbert

Thickness and Temperature Dependence of the Dielectric Function of Bi$_{\mathrm{2}}$Se$_{\mathrm{3}}$

POSTER

Abstract

We have determined the dielectric functions of a series of Bi$_{\mathrm{2}}$Se$_{\mathrm{3}}$ films grown on sapphire substrates. Temperature dependent in-situ ellipsometry spectra were obtained for several samples with varying thicknesses ranging from 5 nm to 60 nm. After the dielectric functions were modeled using the in-situ spectra, they were represented by Kramers-Kronig consistent oscillators. We observe that the dielectric function of Bi$_{\mathrm{2}}$Se$_{\mathrm{3\thinspace }}$has a slight thickness dependence and that it also varies with temperature. Specifically, the oscillators red-shift as temperature increases, which was modeled using a Bose-Einstein distribution.

^*The work at Kenyon College was supported by the NSF grant DMR-2004812

Authors

Xiaoyu Wang
- Department of Physics, Kenyon College, Gambier, Ohio 43022, USA
Frank Peiris
- Department of Physics, Kenyon College, Gambier, Ohio 43022, USA
Maria Hilse
- Department of Material Science and Engineering, Pennsylvania State University, State College, Pennsylvania 16802, USA.
- Department of Materials Science and Engineering, Pennsylvania State University, State College, Pennsylvania 16802, USA
Roman Engel-Herbert
- Department of Material Science and Engineering, Pennsylvania State University, State College, Pennsylvania 16802, USA.
- Department of Materials Science and Engineering, Pennsylvania State University, State College, Pennsylvania 16802, USA