Optical properties and electronic band structure of ZnIn2Te4 -: art. no. 085208

Optical properties of the defect-chalcopyrite-type semiconductor ZnIn2Te4 have been studied by optical absorption, spectroscopic ellipsometry, and x-ray photoelectron spectroscopy. Optical absorption measurements suggest that ZnIn2Te4 is a direct-gap semiconductor having a band gap of similar to 1.40 ev. The complex dielectric-function spectra epsilon (E)=epsilon (1)(E)+i epsilon (2)(E), measured by spectroscopic ellipsometry, reveal distinct structures at energies of the critical points in the Brillouin zone. Analysis of the numerically derived epsilon (E) spectra facilitates the precise determination of the critical point parameters (energy position, strength, and broadening). By performing the band-structure calculation, these critical points are successfully assigned to specific points in the Brillouin zone. The measured x-ray photoelectron spectrum is also presented along with the density-of-states N(E) calculation.