Phototransistors

A phototransistor is a type of transistor that is sensitive to light. It is a light-sensitive semiconductor device that is used to detect and amplify light signals. Phototransistors are made up of a semiconductor material, such as silicon or germanium, and have three layers: the emitter, the base, and the collector. When light strikes the base, it creates electron-hole pairs, which can then be used to control the flow of current between the emitter and the collector. Phototransistors are commonly used in a variety of applications, including light sensors, proximity sensors, and optical switches. They are known for their high sensitivity, low power consumption, and fast response time.