Diffusion-to-streaming transition in a two-dimensional electron system in a polar semiconductor

Hot-electron transport is studied for a two-dimensional electron gas coupled to longitudinal-optical (LO) phonons. At low electric fields the electron motion is diffusive while at high electric fields it is streaming. We develop a diffusion-to-streaming transition model and compare the results with those from the momentum-balance equation, the energy-balance equation, and the Monte Carlo method.