successfully used to determine the refractive index n and absorption coefficient α of
undoped gallium nitride film over the spectral range of 0.78–4.77 eV of photon energy. The
SE measurement is carried out at angle of incidence of 60° over the 1.5–4.77 eV energy
range and optical transmission measurement over the 0.78–3.55 eV energy range. The
refractive index n and absorption coefficient α obtained by both methods show unique …