Bremsstrahlung-isochromat study of the layered compounds InSe, TiSe2, SnSe2, SnS2, and Bi2Te3

Abstract

We present bremsstrahlung-isochromat spectra (BIS) for the layered compounds InSe, ${\mathrm{TeSe}}_2$, ${\mathrm{SnS}}_2$, ${\mathrm{SnS}}_2$, ${\mathrm{SnSe}}_2$, and ${\mathrm{Bi}}_2$ ${\mathrm{Te}}_3$ at a photon energy of 1486.6 eV. The spectra exhibit several sharp peaks in the lower conduction bands. These spectral features are compared with theoretical calculations of the density of states and with optical data. In several cases, discrepancies between the BIS spectra and the optical spectra confirm that large core excitonic shifts occur for layered compounds.