Monte Carlo Study of the Dynamic Screening Effect in Doped GaN

Monte Carlo simulations of hot electron transport in n-type GaN when the interaction of the electrons with polar optical phonons is dynamically screened shows the effects of antiscreening at carrier densities of (1-5)x1024 m-3. At these densities full coupling between the Plasmon-phonon systems could be ignored to a first approximation together with degeneracy. Our calculations used the Lindhard formalism with Fermi-Dirac distribution and with neglecting the collisional damping when dynamic screened electron phonons scattering rates calculated. The screened scattering rate is strongly enhanced at low electron temperature and high carrier concentrations due to antiscreening property of inverse dielectric function. Antiscreening delays runaway and intervalley transfer to higher valleys. The peak drift velocity is enhanced and as result, so is the peak valley ratio.