Reflectance Spectroscopy Of Excitonic States In Gan/6h-Sic

This paper considers low-temperature (T=6 to 60K) measurements of excitonic reflectance spectra of single-crystal GaN films grown on 6H-SiC substrates. A theoretical analysis of the spectra was carried out in terms of a many-oscillator classical model. As a result, the basic parameters of the excitonic states have been determined. The parameters were analyzed in the framework of the quasicubic model for a wurtzite-type crystal. The values of a crystal field (11 meV) and spin-orbit (14.5 meV) splittings were estimated. It was shown that the quasicubic model does not describe well GaN crystal and the above values can be treated only as a rough approximation.