Linear screening in strongly nonequilibrium semiconductors is studied by a Boltzmann-equation approach. In determining the nonequilibrium susceptibility χ(q,ω), the correct distribution function is used, and the effects of scattering are included. As an application, we find that the ionized-impurity–scattering rate in a bulk semiconductor is significantly enhanced by a uniform, static electric field producing a drift velocity equal to the thermal velocity. A small-q limit of χ(q,ω) is related to the longitudinal noise temperature $T_n$,? by a Debye-Hückel–type relation χ=-n/$k_B$$T_n$,?.

• Received 14 November 1988

DOI:https://doi.org/10.1103/PhysRevB.39.8464