As the electron-hole recombination occurs in p region, the p layer is kept at the top and the anode is deposited at the edge of the p layer to have maximum light emission. The layer of P-type material and N-type material is combined together on top of each other with an active region between them. Therefore, the p-layer is designed to be kept at the top of the LED. The electrons move and combine with holes in the p-layer. As we know that light emits when an electron and hole combines. The electrons and holes recombine in this region. The active region is also known as the depletion region. The active region has an equal amount of electrons and holes therefore there are no majority charge carriers. The N-layer had the majority of electrons while the P-layer has a majority of holes. P-type semiconductor layer, N-type semiconductor layer and active region. Instead of Silicon and germanium, gallium arsenide, gallium phosphide, and indium phosphide compounds are used depending on the color of emitting light. The property of a material to convert electrical energy into light energy is called Electro-Luminance. Not every material is capable to have such property. In other words, when charge carriers electrons and hole combines, they release light energy. Light energy is generated when an electron from a higher energy band falls into the low energy band and releases energy. The junction is covered in transparent epoxy to direct the light emitting from the junction in all directions. It is a simple PN junction diode that radiates light in forward bias.

In other words, LED is a special type of diode that converts electrical energy into light energy. It is a type of diode that emits light when a current pass through it. LED is a short form of Light Emitting Diode. VI Characteristics of Light Emitting Diode.Output Characteristics of Light Emitting Diode.Symbol and Leads Identifications of Light Emitting Diode.Related Posts: What is a Diode? Construction and Working of PN Junction Diode.This article explains LED in detail with its working principle, construction, etc. It is used for illuminating streets, homes and industries. It is used in every electronic equipment that is used to display any kind of information.

The invisible light (infrared) is used in a remote control. LED can generate visible as well as invisible light. PN junction diodes are invented way before LED, it wasn’t until 1962 Nick Holonyak thought of a special type of diode that converts electrical energy into light energy. It is available in every size, shape and color. Unlike an incandescent bulb, it does not get hot, therefore It is an energy-efficient light source. It is a special type of diode that converts electrical energy into light energy. It is a light source and in form of a small bulb that can be fitted inside a circuit. LED or Light Emitting Diode is the most used electronic component in our daily life. Light Emitting Diode – LED: Construction, Operation, Types and Applications

Cathode of led