Photocurrent is the current that flows through a photosensitive device, such as a photodiode, as the result of exposure to radiant power. The photocurrent may occur as a result of the photoelectric, photoemissive, or photovoltaic effect. The photocurrent may be enhanced by internal gain caused by interaction among ions and photons under the influe... Found on http://en.wikipedia.org/wiki/Photocurrent
that part of the output current of a photoelectric detector which is caused by incident radiation NOTE - In photomultipliers a distinction must be made between the cathode photocurrent and the anode photocurrent. Found on http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=845-05-52