2Depto. de Ingeniería Eléctrica, CINVESTAV-IPN

CdO is a material with optical properties similar to CdS, but with the advantage of having degenerated electrical states. This characteristics allows for a good electrical conductivity without any additional dopant [1]. Cadmium oxide has a cubic crystalline structure (NaCl), and it is usually n-type [2]. The optical properties previously reported on this material are the absorption coefficient, where the energy band gap has been determined to be 2.67 eV associated with direct transitions. In the direct transitions have been observed at low energies with the characteristic 1.09 eV transition energy. In this work we report spectral ellipsometry measurements around the direct band gap of CdO. The effective medium model has been used to determine the dielectric function of the material, as well as the existence of a second face form with graphite.

[1] M. Ortega-López, A. Morales-Acevedo, Rev. Mex. de Física, 42,

776(1996).

[2] Z.M. Jarzebzki, Oxide Semiconductors, edited by B.R. Pamplin,

Pergamon Press (1973) p. 239.