Optical properties and electronic energy-band structure of CdIn sub(2)Te sub(4)

Optical properties of a defect-chalcopyrite-type semiconductor CdIn sub(2)Te sub(4) have been studied by optical absorption, spectroscopic ellipsometry (SE), and thermoreflectance (TR) measurements. Optical absorption measurements suggest that CdIn sub(2)Te sub(4) is a direct-gap semiconductor having the bandgap of 61.22 eV at 300 K. The complex dielectric-function spectra, e(E) = e sub(1)(E) + ie sub(2)(E), measured by SE reveal distinct structures at energies of the critical points in the Brillouin zone. TR spectroscopy facilitates the precision determination of the critical point energies. By performing the band-structure calculation, such critical points are successfully assigned to specific points in the Brillouin zone.