Light-induced reversible conductivity changes in silicon-on-insulator nanowires

Silicon-on-insulator (SOI) samples are preferred for extention of the metal-oxide-silicon technology. Here, we report a reversible change in electrical conductivity in dark conditions of a 20-nm-thick SOI layer, induced by illumination. In spite of some similarities with the Staebler–Wronski effect in hydrogenated amorphous silicon, we point out important differences such as the crystalline nature of our silicon film, the lack of hydrogen and a much shorter relaxation time at ambient temperature. This time can even be reduced by application of a vertical electric field. We suggest that interface traps play a major role in this mechanism. Finally, we noticed a conductivity change between ambient light and dark conditions.