Nonlinear transport properties of Ⅲ-nitrides in electric field

摘要

We consider the transport properties of polar direct-gap semiconductors in an electric field, specializing the numerical calculation of the general theory to the case of n-doped Ⅲ-nitrides, in particular, GaN, AlN, and InN. The nonequilibrium thermodynamic state of these materials-characterized by the variables so-called quasitemperature, quasichemical potential, and drift velocity of the carriers, and the quasitemperatures of longitudinal optical and acoustical phonons—is studied. The evolution equations of these variables-which are highly nonlinear-are derived, and the transient regime and the ensuing steady state are analyzed. The nonlinear transport is characterized and its main properties are discussed. In one case comparison with a recent Monte Carlo calculation is made and good agreement is obtained. In this paper we mainly consider the ultrafast transient, and in the following paper the steady state.