Spectral ellipsometry investigation of Zn0.53Cd0.47Se lattice matched to InP

Spectral ellipsometry at 300 K, in the range 0.8-5.5 eV, has been used to study the bulk and surface oxide properties of a molecular-beam-epitaxy grown Zn0.53Cd0.47Se/InP film (approximate to 1 mu m thick). We have observed the direct gap E-0, which exhibits a well-defined excitonic structure, its spin-orbit split component E-0+Delta(0), as well as the spin-orbit split E-1, E-1+Delta(1) doublet. The experimental data over the entire measured spectral range (after oxide removal) have been fit using a model dielectric function based on the electronic energy-band structure near critical points plus excitonic and Coulomb enhancement effects. The influence of a native oxide on the optical properties also was investigated.