Extension of the collision-time tensor to the case of inelastic scattering mechanisms: Application to GaAs and GaN

In this paper we propose a generalization of the collision time tensor recently introduced for the description of anisotropic but elastic scattering mechanisms to the case of inelastic collision mechanisms (optical phonons). II is shown that this approach brings noticeable corrections to the standard relaxation time approach as soon as the temperature is lower or of the order of the Debye temperature associated with the optical phonon energy. Numerical applications are presented in the case of GaAs and GaN. They show that optical phonon scattering starts to be the preeminent scattering mechanism well below room temperature for GaAs while acoustical phonon scattering dominates up to 500 K for GaN.