Surface Morphology and Differential Tunneling Conductivity in Multicomponent Solid Solutions (Bi, Sb, Sn, Ge)2(Te, Se)3

Abstract

The morphology of the interlayer surface and the spectra of differential tunneling conductivity in solid solutions (Bi, Sb, Sn, Ge)2(Te, Se)3 has been studied by scanning tunneling microscopy and scanning tunneling spectroscopy. Surface defects associated with distortions of surface electronic states as a result of atomic substitution and with the formation of intrinsic defects formed during the growth of solid solutions are systematized. The position of the Dirac point and its fluctuations relative to the mean value are determined, the levels of impurity surface defects are found, and their energy depending on the composition of the solid solution, the value of the Seebeck coefficient, and the power parameter are calculated. The surface concentration of Dirac fermions is calculated and the compositions are established in which the contribution of surface states increases due to an increase in the concentration of fermions and due to an increase in the Fermi velocity and mobility of fermions in the surface layer.