MOBILITY AND TEMPERATURE OF ELECTRONS IN POLAR SEMICONDUCTORS,

The transport of electrons due to an electric field in a polar semiconductor is treated with the assumption of a displaced Maxwellian velocity distribution. It is assumed that the only scattering is from optical phonons. Exact expressions are obtained for the drift velocity and the electron temperature. At low lattice temperatures they are substantially different from earlier, approximate results. In particular, if the lattice temperature is less than 0.375 theta, where theta is the characteristic temperature of the optical phonons, the electron temperature is reduced when a weak electric field is applied. For higher field strengths the electron temperature is higher than the lattice temperature, but considerably below that predicted by the approximate theory. Author