  We investigate the bias-induced insulator-metal transition in organic
electronics devices, on the basis of the Su-Schrieffer-Heeger model combined
with the non-equilibrium Green's function formalism. The insulator-metal
transition is explained with the energy levels crossover that eliminates the
Peierls phase and delocalizes the electron states near the threshold voltage.
This may account for the experimental observations on the devices that exhibit
intrinsic bistable conductance switching with large on-off ratio.
