Open AccessТопологические поверхностные состояния фермионов Дирака в термоэлектриках n-Bi-=SUB=-2-=/SUB=-Te-=SUB=-3-y-=/SUB=-Se-=SUB=-y-=/SUB=-
Author(s) -
Л.Н. Лукьянова,
И. В. Макаренко,
О. А. Усов,
P. A. Dementev
Publication year - 2019
Publication title -
fizika i tehnika poluprovodnikov
Language(s) - English
Resource type - Journals
eISSN - 1726-7315
pISSN - 0015-3222
DOI - 10.21883/ftp.2019.05.47557.15
Subject(s) - dirac fermion , condensed matter physics , thermoelectric materials , scanning tunneling microscope , seebeck coefficient , thermoelectric effect , fermi level , density of states , scanning tunneling spectroscopy , fermi energy , surface states , topological insulator , band gap , x ray photoelectron spectroscopy , physics , materials science , fermion , electron , surface (topology) , quantum mechanics , geometry , nuclear magnetic resonance , mathematics
Topological surface states of Dirac fermions in n-Bi2Te3−ySey thermoelectricsL.N. Lukyanova, I.V. Makarenko, O.A. Usov, P.A. DementevIoffe Institute, 194021 St. Petersburg, RussiaAbstract In n-Bi2Te3 and n-Bi2Te3−ySey thermoelectrics, the surface states of Dirac fermions of the interlayer van der Waals plane (0001) were studied by scanning tunneling microscopy (STM) and spectroscopy. The surface morphology and modulated line profiles of the images in tunneling microscopy is determined by local distortions of the surface electron states density and depend on the composition. The Dirac point ED of the studied compositions is localized in the energy gap, and it shifts to the top of the valence band with increase of Se content in the solid solutions. The dependence between Dirac surface state parameters (the Dirac point position, the Fermi velocity, the fermion surface concentration) and thermoelectric properties (Seebeck coefficient and the power factor) is established for the thermoelectrics studied.