Electronic Photodiodes and Photocells

Pacer supplies a wide range of photodiodes and photocells from leading manufacturers, as well as avalanche (higher sensitivity) and PIN photodiodes. A photodiode is a semiconductor device with a PN junction or PIN structure that can convert light into either current or voltage, depending on the mode of operation. In operation, a photon striking the diode excites an electron, creating a free electron and a hole. If the absorption occurs in the junction's depletion region, or one diffusion length away from it, these carriers are swept from the junction by the built-in field of the depletion region. Thus holes move toward the anode, and electrons toward the cathode, and a photocurrent is produced. The two main modes of photodiode operation are photovoltaic mode, which produces a voltage, and photoconductive mode, which produces a photocurrent that is is linearly proportional to the illuminance. Avalanche photodiodes have similar photodiode structures, but operate with higher reverse bias. This allows each photo-generated carrier to be multiplied by avalanche breakdown, creating internal gain that increases the effective responsivity of the device. Click on the category above for data sheets. Pacer also offers a range of photodiodes and PIN photodiodes from Kodenshi and TT Optek. More information on Kodenshi Photodiodes - parameters and data More information on Optek's photodiode range