AVS 62nd International Symposium & Exhibition
    Spectroscopic Ellipsometry Focus Topic Thursday Sessions
       Session EL+AS+BI+EM-ThA

Paper EL+AS+BI+EM-ThA8
Structural and Ellipsometric Analysis of the Topological Insulator Bi2Se3

Thursday, October 22, 2015, 4:40 pm, Room 112

Session: Optical Characterization of Nanostructures and Metamaterials
Presenter: Avery Green, SUNY Polytechnic Institute
Correspondent: Click to Email
Topological Insulator (TI) materials have been the subjects of increasing scientific interest in the last decade. Their spin-momentum locked Dirac cone surfaces and insulating bulks have resulted in new directions in physics research and new spintronic devices. Though these materials have been thoroughly described in theory, the experimental realization and measurement of these surface states has been problematic, due to various crystalline defects. Theory predicts that TI surface states are protected against local defects, but it is essential to study the effects of global perturbations caused by surface oxidation, stoichiometric aberrations, and significant structural defect densities. The aim of this study is to measure the time-dependent dielectric function of the Bi2Se3 surface and bulk in air, using a dual rotating compensator spectroscopic ellipsometer. These data are backed up with various metrological measurements (AFM, cross-sectional TEM, EDS) to confirm surface topology and oxide thickness. This analysis of optical properties and oxide formation will, in the future, be used to optimize the Bi2Se3 flake thickness identification process, and provide a control for further necessary structural analysis, as stated above.