The self-consistent analysis of drift-diffusion transport in strong inhomogeneous electric fields showed that the local mobility was determined by the “field parameter” f(r) = rEc(r)·rEF(r), rather than the electric field rEc(r)/e or the quasi-Fermi potential gradient rEF(r)/e, as was usually assumed. This takes place at both high and low carrier densities. The methods for derivation of µ(f) in both cases were presented. The analysis was applied to numerical simulation of a p-i-n photodiode, and it was shown that the use of µ(F) with F(r) = |rEc(r)/e| results in grossly exaggerated carrier drift velocities. The implications for drift-diffusion models used in commercial device simulators were discussed.

Nonequilibrium Drift-Diffusion Transport in Semiconductors in Presence of Strong Inhomogeneous Electric Fields. N.A.Zakhleniuk: Applied Physics Letters, 2007, 89[25], 252112