Finite-temperature band gap renormalization in highly photoexcited GaN epilayers

Room-temperature luminescence spectra were investigated in GaN epilayers un der extremely high photoexcitation. In a variety of samples, dynamics of th e spectra with increase of the excitation intensity was found to exhibit a high-carrier-temperature regime of the electron-hole plasma. This regime wa s proved by a mutual relation of the parameters deduced from the spectra (t he peak position and intensity of the luminescence band, as well as carrier temperature) in accordance with the finite-temperature band gap renormaliz ation theory.