Structural, optical and electronic properties of the wide bandgap topological insulator Bi1.1Sb0.9Te2S

Khatchenko Y.E.; Yakushev M.V.; Seibel C.; Bentmann H.; Orlita M.; Golyashov V.; Ponosov Y.S.; Stepina N.P.; Mudriy A.V.; Kokh K.A.; Tereshchenko O.E.; Reinert F.; Martin R.W.; Kuznetsova T.V.

doi:10.1016/j.jallcom.2021.161824

Инд. авторы:	Khatchenko Y.E., Yakushev M.V., Seibel C., Bentmann H., Orlita M., Golyashov V., Ponosov Y.S., Stepina N.P., Mudriy A.V., Kokh K.A., Tereshchenko O.E., Reinert F., Martin R.W., Kuznetsova T.V.
Заглавие:	Structural, optical and electronic properties of the wide bandgap topological insulator Bi1.1Sb0.9Te2S
Библ. ссылка:	Khatchenko Y.E., Yakushev M.V., Seibel C., Bentmann H., Orlita M., Golyashov V., Ponosov Y.S., Stepina N.P., Mudriy A.V., Kokh K.A., Tereshchenko O.E., Reinert F., Martin R.W., Kuznetsova T.V. Structural, optical and electronic properties of the wide bandgap topological insulator Bi1.1Sb0.9Te2S // Journal of Alloys and Compounds. - 2022. - Vol.890. - Art.161824. - ISSN 0925-8388. - EISSN 1873-4669.
Внешние системы:	DOI: 10.1016/j.jallcom.2021.161824; WoS: 000706835200004;
Реферат:	eng: Successful applications of a topological insulator (TI) in spintronics require its bandgap to be wider then in a typical TI and the energy position of the Dirac point in the dispersion relations to be away from the valence and conduction bands. In this study we grew Bi1.1Sb0.9Te2S crystals and examined their elemental composition, structural, optical and electronic properties as well as the electronic band structure. The high structural quality of the grown crystals was established by X-ray diffraction and Raman spectroscopy. Angular resolved photoelectron spectroscopy demonstrated a near parabolic character of the valence and conduction bands and a direct bandgap of 0.36 eV. The dispersion relations also revealed a Dirac cone, confirming the topological insulator nature of this material, with the position of the Dirac point being 100 meV above the valence band maximum. Far infrared reflectivity spectra revealed a plasma edge and two phonon dips. Fitting these spectra with theoretical functions based on the Drude-Lorentz model allows determination of the high frequency dielectric constant (41.3), plasma frequency (936 cm(-1)) and the frequencies of two infrared phonons (177.7 cm(-1) and 77.4 cm(-1)). (C) 2021 Elsevier B.V. All rights reserved.
Ключевые слова:	SURFACE; TETRADYMITE; CRYSTAL-STRUCTURE; Optical reflectivity; Far infrared; ARPES; Electronic structure; Bi1.1Sb0.9Te2S; Topological insulator; BI2SE3;
Издано:	2022
Физ. характеристика:	161824