Modeling of the band structure of Bi 2Se 2Te crystallites deposited on Si and SiO 2 substrates

• Published in: Physica. B, Condensed matter Vol. 349; no. 1; pp. 143 - 148
• Main Authors: Jankowska-Sahraoui, E., Slezak, A., Kimura, J.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2004
• Subjects: Band energy structure of crystals; Bismuth telluride and selenide; Band energy structure of crystals; Bismuth telluride and selenide; Ky72.40
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2004.02.013

The band structure (BS) of crystalline Bi 2Se 2Te both pure as well as deposited on Si or SiO 2 (substrates) was calculated for the first time. The calculation approach consists of an orthogonalization of the plane wave basis set with respect to the core-like orbitals and the application of the Perdew–Alder exchange-correlation scheme. In addition, a virtual crystal approach was applied. Experimental ellipsometric spectra were used as a criterion of the advantages of the different calculation techniques. The results of traditional one-electron methods of BS calculations, using norm-conserving pseudo-potential (NCPP), and full linear augmented plane wave (FLAPW), were compared with the experimental data. Better agreement with experiment is achieved when the NCPP wave functions are orthogonalized to the 4dBi core-like states. Concerning the LMTO and the FLAPW all-electron methods, only appropriate application of the virtual crystal approximation to these approaches produces results that are in agreement with ellipsometric experimental data.