PHOTOSTIMULATED MESOSCOPIC CURRENT FLUCTUATIONS IN A-SI BASED MICROSTRUCTURES

Photostimulated two-level switchings of a vertical current are observe d in thin (L=200 Angstrom) amorphous silicon layers with a submicron e lectrical contact area (S=0.5X0.5 mu m). The switching frequency incre ases with the photon flux. The conductivity fluctuations are explained on the basis of a microscopic nonlocal Staebler-Wronski effect. It is shown that the elementary event of formation of a metastable defect i s accompanied by a reorganization of the system over along distance of similar to 2500 Angstrom. (C) 1996 American Institute of Physics.