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 ≈3.8×10 5 cm/ s at an electric field of F≈8.9×10 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).