Electroreflectance Of Hexagonal Gallium Nitride At The Fundamental And E-1 Spectral Regions

We have measured the room-temperature electroreflectance (ER) of hexagonal gallium nitride. Our measurements were obtained at the fundamental optical gap and at the E-1 critical point regions. The measurements were performed using front contact ER. In the fundamental region, the ER spectra were found to be of excitonic nature and in the low field regime. In the E-1 region, the ER spectra were also in the low field regime, but were fitted with two-dimensional critical points. (C) 2003 American Institute of Physics.