The effect of hot phonons on the drift Velocity in GaN/AlGaN two dimensional electron gas

Abstract

We present the effect of hot-phonon production on the high-field drift velocity in the steady state in GaN/AlGaN heterostructures. The results are compared with a model taking into account the effect of hot phonon production on the high-field transport of electrons. Experimental results show that the drift velocity saturates at around v(d) approximate to 3.8 x 10(5) cm/s at an electric field of F approximate to 8.9 x 10(2) V/cm at 3.8 K. The theoretical calculations show that the enhancement of the momentum relaxation rate due to the production of non-drifting hot phonons reduces the drift velocity at high field. The reduction in the drift velocity increases with increasing population of non-drifting non-equilibrium phonons (LO phonons).