Electron energy relaxation in wurtzite ZnO and GaN

Experimental data and Monte-Carlo modeling of hot-electron fluctuations are used for investigation of hot-electron energy relaxation in donor-doped bulk wurtzite ZnO and GaN subjected to a pulsed dc. The extracted electron energy relaxation time depends on the electron density. The experimental value of 0.84 ps is obtained at 5.5×10¹⁷ cm^-3 in a reasonably good agreement with the results reported from time-resolved optical measurements. The relaxation becomes faster at a lower electron density where the optical data are not available. The density dependence is discussed in the frame of hot-phonon effect.