Hot-electron dynamics and terahertz generation in GaN quantum wells in the streaming transport regime

We study hot-electron transport and the dynamic negative differential conductivity in a GaN/AlGaN quantum well by using the Monte Carlo method. We find that the electron-electron interaction, the nonequilibrium polar optical phonon, and the electron gas degeneracy may influence the electron transport property and destroy the spindle-shaped distribution in the streaming transport regime. Our simulation results suggest that the hot phonon effect, and the electron gas degeneracy are more important in the determination of electron steady state velocity-field characteristics, while the electron-electron interaction is dominant in the disturbance of the electron periodic motion. We conclude that terahertz generation using the electron dynamic negative differential conductivity is only possible at relatively low electron density before the electron-electron interaction steps into role.