Optical Absorption Spectrum of a Thin CuFeS₂ Film

Abstract

The CuFeS₂ films were prepared by means of the close-spacing chemical vapor deposition technique, and the optical absorption spectra of the films were measured. Distinctive feature of the spectrum is the existence of an absorption edge at 3.7 eV in addition to a broad band located between 0.6 eV and 3.7 eV with a maximum around 2 eV. One can conclude from this observation that the absorption edge (0.6 eV) of CuFeS₂ reported previously is the foot of the ‘charge transfer’ transition and that the extra absorption edge (3.7 eV) found in the present work corresponds to the fundamental absorption edge of the nonmagnetic analogs.