ELECTROSTATIC SCREENING DUE TO NONEQUILIBRIUM CARRIERS

A simple calculation shows how the electrostatic screening length due to non-equilibrium electrons differs significantly from that for an el ectron ensemble which is in thermodynamic equilibrium. Its dependence upon the field, the lattice temperature and the effective mass is dete rmined by the prevalent recombination processes, type of trapping cent er and the dominant scattering mechanisms of the free carriers. The nu merical result for high purity Ge at 10 K shows that the screening len gth for the non-equilibrium electrons at a field of 5.5 v cm(-1) may a ssume a value less than half of that for the electrons that are in the rmodynamic equilibrium. Copyright (C) 1996 Published by Elsevier Scien ce Ltd