Velocity overshoot onset in nitride semiconductors

A theoretical study on the electron drift velocity and some nonequilibrium thermodynamic characteristics of wurtzite GaN, AlN, and InN is presented. I t is based on a nonlinear quantum kinetic theory which provides a descripti on of the dissipative phenomena developing in the system. The ultrafast tim e evolution of the electron drift velocity and quasitemperature is obtained , and overshoot effects are evidenced on both. The overshoot onsets are sho wn to occur at 20 kV/cm in GaN, 60 kV/cm in AlN, and 10 kV/cm in InN, elect ric field intensities which are considerably smaller than those that have b een recently derived resorting to Monte Carlo simulations. (C) 2000 America n Institute of Physics. [S0003-6951(00)03914-0].