Photodiodes capture light.
Based upon a photodetector, which senses light upon exposure, photodiodes convert light into electric current. The more light that strikes the photodiode, the more current it generates. This is the opposite of the functioning of a light bulb, which receives electric current and then produces light. All photodiodes exhibit the same basic principles, but there are different types for different uses.
Solar Cell
Turning sunlight into energy.
A solar or photovoltaic cell is a basic device, which can be found on rooftops and other locations, is a type of photodiode that serves as an alternative source of energy. Solar cells take sunlight and convert it into electricity. The more sunlight that strikes the solar cells, the more electricity generated. Large-scale production requires many cells in several panels called arrays. This type photodiode requires silicon, the substance that generates the electricity. When placed in the presence of light, silicon's electrons become excited and that action generates the electric current.
Avalanche
Named for the so-called avalanche process, the avalanche type of photodiode uses a photodetector to sense light that generates electric current. The difference occurs when the current is subjected to high voltage of even tens or hundreds of volts. The original electrons, based upon the voltage, create additional carriers, or photomultipliers. The entire process occurs in a short time, cascading like an avalanche. The entire photocurrent becomes amplified and thus very sensitive, making this photodiode useful as a sensitive detector in optical fiber communication, high-speed laser scanning and imaging.
P-I-N
Named for three regions in a photodiode designated by the letters "p, i and n", the P-I-N type of photodiode utilizes a procedure of doping, or filling, two of the regions with silicon while the middle region, or "i," remains undoped. The electrons are attracted to the "i" region, where they develop a high efficiency and a higher-detection bandwdith. These qualities make this type of photodiode attractive for uses requiring a large bandwidth, like optical fiber communications.
Tags: type photodiode, electric current, generates electric, generates electric current, light that, optical fiber
