Decrease of electron temperature by electric fields

The momentum distribution of electrons in semiconductors in the presence of electric fields is in the hot electron theory frequently assumed to be a displaced Maxwell distribution, corresponding to a temperature T larger than the temperature T 0 in the absence of the field. We demonstrate in the present paper that conditions exist in which T < T 0 , although the mean energy of an electron is larger than 3/2 kT 0 . Detailed consideration of various types of electron scattering leads to the suggestion of a number of materials in which the effect T < T 0 should be observable.