what is photodiode

A photodiode is a type of semiconductor diode that converts light energy into electrical current. It operates in reverse bias condition, with the positive (p) side connected to the negative terminal of a power supply and the negative (n) side connected to the positive terminal. When photons of sufficient energy strike the diode, they create electron-hole pairs, resulting in the generation of a photocurrent. Photodiodes are used in various applications, including scientific and industrial instruments to measure light intensity, as receivers of data encoded on an infrared beam, and in optocouplers for signal transmission between circuits without a direct metallic connection. They are also utilized in cameras as photo sensors and in charge-coupled devices.