Hot-phonon effect on power dissipation in a biased Al_xGa_1−xN∕AlN∕GaN channel

The Monte Carlo simulation of hot-electron energy dissipation is carried out for a biased AlGaN∕AlN∕GaN channel. The conduction band profile and electron wave functions are calculated through self-consistent solution of Poisson and Schrödinger equations. Nonelastic scattering of electrons on acoustic phonons and nonequilibrium longitudinal optical (LO) phonons is included. The nonequilibrium LO phonons are treated in terms of hot-phonon lifetime. The dependence of electron temperature and dissipated power on the applied electric field is obtained from the Monte Carlo simulation. The experimental results on noise temperature and current as functions of electric field strength applied along the channel are presented, and the dependence of the supplied electric power on the inverse electron temperature is evaluated. The best agreement between the Monte Carlo results and the experimental data is obtained for the hot-phonon lifetime τ_ph=1 ps.