The electric field dependence of carrier temperature in semiconductors

It has recently been predicted that in a suitable semiconductor the electron temperature may be reduced below the lattice temperature by an applied electric field. These calculations have either employed a three-term expansion of the electronic distribution function, or neglected all scattering other than that arising from polar optical modes. In the present paper the electron temperature is calculated as a function of electric field for both polar and non-polar semiconductors, including polar optical, deformation potential optical and acoustic, and intervalley scattering without expansion of the distribution function. Results are presented for n-type GaAs, InSb, Si and GaP. Finally, in discussing the approximations which remain in this theory, particular reference is made to p-type Ge, for which experimental data are available.