Photodiode example

What is a photodiode?

Photodiode is a type of semi conducting device with PN junction. Between the p (positive) and n (negative) layers, an intrinsic layer is present. The photo diode accepts light energy as input to generate electric current. It is also called a Photodetector, Photo Sensor, or Light Detector.

What are the different types of photodiodes?

There are four main types of photodiodes: PN Photodiode: Basic, fast, and low cost. PIN Photodiode: Includes an intrinsic layer for high sensitivity. Avalanche Photodiode (APD): Provides internal gain for low-light detection. Schottky Photodiode: Metal-semiconductor junction, offers the fastest response time.

What happens when a photodiode is used with an external circuit?

When photodiodes are used with external circuits, they are connected to a power source in the circuit. The amount of current produced by a photodiode will be very small.

Where can I find a photodiode?

You will find photodiodes in systems such as infrared remote control circuits, beam interruption relays and intruder alarm circuits. There's another variant of photodiode which uses lead-sulfide (PbS) and there working characteristic is quite similar to LDRs but are designed to respond only to the infrared range lights.