Role of electron-electron collisions in high field conduction in Nitrides

Role of electron-electron collisions in semiconductors is to exchange energy and momentum among the conduction electrons and to express the electron distribution in terms of electron temperature and electron drift velocity. This role takes particular importance when the external electric field produces large disparities in the energy distribution of electrons. Such disparities are introduced in polar semiconductors such as Nitrides. Electron-electron collisions give rise to heating or cooling of the electron gas. Heating is widely accepted but cooling in steady state and transient currents is new as is shown in this paper. It is also shown that the overshooting of electron velocity in transient currents in Nitrides is related to the electron cooling.