High Quality Content by WIKIPEDIA articles! Photoconductivity is an optical and electrical phenomenon in which a material becomes more electrically conductive due to the absorption of electro-magnetic radiation such as visible light, ultraviolet light, infrared light, or gamma radiation. Photoconductivity is a specific type of radioconductivity, the phenomenon when a material becomes more electrically conductive due to any form of radiation, including electromagnetic radiation, alpha particle radiation, beta particle radiation, muon radiation, or more exotic forms of radiation. When light is absorbed by a material like a semiconductor, the number of free electrons and electron holes changes and raises the electrical conductivity of the semiconductor.