1) Photocell 1) Sensor in a CD player 
A photodiode is a semiconductor device that converts light into current. The current is generated when photons are absorbed in the photodiode. A small amount of current is also produced when no light is present. Photodiodes may contain optical filters, built-in lenses, and may have large or small surface areas. Photodiodes usually have a slower re...
(from the article `radiation measurement`) Alternatively, the light can be measured using a solid-state device known as a photodiode. A device of this type consists of a thin semiconductor ... ...on the photoelectric effect have several desirable properties, including producing a current that is directly proportional to light intensity ...
photoelectric detector, in which a photocurrent is generated by absorption of optical radiation in the neighbourhood of a PN junction between two semiconductors or a junction between a semiconductor and a metalphotoelectric device in which absorption of electomagnetic radiation in the junction and its neighbourhood or at a contact between a semiconductor and a metal, produces a change of resistance or a change of voltagean optical detector in which a photocurrent is generated by absorption of radiation in the neighbourhood of a PN junction between two semiconductors compositions or of a junction between a semiconductor and a metalphotoelectric detector in which a photocurrent is generated by absorption of optical radiation in the neighbourhood of a p-n junction between two semiconductors or a junction between a semiconductor and a metal
(Digital cameras and photo printers) A semiconductor which measures or converts light into an electrical current. Photodiodes are commonly used in scanners, CCD sensors, and exposure meters.
A diode which acts as a photodetector.
A photodiode is a two electrode semiconductor device with an optical radiation sensitive junction in which the reverse current varies with the illumination. The wavelength sensitivity is a function of the materials used in the device. Silicon photodiodes are sensitive through most of the visible spectrum. InGaAs photodiodes are sensitive in the NIR...
A type of semiconductor device in which a PN junction diode acts as a photosensor.