What are the main types of photo sensors?
A photosensor is an electronic component that detects the presence of visible light, infrared transmission (IR), and/or ultraviolet (UV) energy. Most photosensors consist of semiconductor having a property called photoconductivity , in which the electrical conductance varies depending on the intensity of radiation striking the material. The most common types of photosensor are the photodiode, the bipolar phototransistor, photoFET (photosensitive field-effect transistor). These devices are essentially the same as the ordinary diode , bipolar transistor , and field-effect transistor , except that the packages have transparent windows that allow radiant energy to reach the junctions between the semiconductor materials inside. Bipolar and field-effect phototransistors provide amplification in addition to their sensing capabilities.
