Hot electrons and holes in highly photoexcited GaN epilayers

In GaN epilayers an increase of the carrier temperature was deduced from th e luminescence spectra under intense quasi-steady-state photogeneration. To account for the measured dependence of the electron temperature on the exc itation power density, all relevant mechanisms of the nonequilibrium-phonon production were considered. Finally, theoretical modeling yielded strong i mplications that, contrary to electrons, hot photogenerated holes maintain no Maxwellian distribution function above the threshold for the optical pho non emission.