TABLE OF CONTENTS This chapter deals with the investigation of the particle transport in gallium arsenide with the help of the multigroup model equations (3.40). The calculations are performed for n-type GaAs at the temperature T L = 300 K. The influence of holes in the valence band is completely neglected. The conduction band is approximated by the ? valley centered at ?0, 0, 0 ?, four equivalent L valleys along ?1, 1, 1 ? and three equivalent X valleys along ?1, 0, 0 ?. All of these valleys are assumed to be spherical and non-parabolic [Conwell and Vassel (1968)].
Concerning the scattering mechanisms, we consider acoustic deformation potential and acoustic piezoelectric scattering. Furthermore, we take into account polar optical, optical deformation potential scattering in the L valleys and impurity scattering, which are all intravalley processes, as well as non-polar optical intervalley scattering. Since the acoustic deformation potential and the piezoelectric scattering are not efficient at 300 K [Conwell and Vassel (1968); Fawcett et al. (1979)], these mechanisms are regarded as being elastic. The ionized impurity scattering is described with the help of the Brooks-Herring model [Brooks and Herring (1951)] and by assuming equal electron and donor concentrations. As for the LO phonons, we include the polar optical interaction and phonon-phonon thermalization processes in their kinetic equations. The material parameters used in our calculations are found in Tab. 4.3 and are taken from [Klemens (1966); Constant (1985); von der Linde...
