Abstract
The dependence of the photo-induced excess conductivity in doping-modulated amorphous silicon on exposure time, light intensity, exposure temperature and boron-doping concentration is investigated. Our results indicate that the excess-conductivity effect arises from charge storage in a novel defect centre. The growth of the excess conductivity is thermally activated and obeys a power-law dependence on exposure time and light intensity, where the exposure-time exponent increases with light intensity.