How Light Emitting Diodes Work ?
When you want to understand how a particular type of diode works, it’s important to understand just what a diode is. A definition from one of several electronics texts shows that a diode is a simple kind of semiconductor. A semiconductor is one of several types of material that has the ability to conduct electrical current at various levels. This is usually achieved by making a semiconductor out of a material that is not a necessarily a good conductor and making sure it has the correct impurities to achieve the desired conducting level.
A light emitting diode (LED) is generally made with a combination material – aluminum/gallium/arsenide. This material has no free electrons so it is a very poor conductor of electrical current. “Doping” the material puts in free electrons or creates spaces for electrons to go into. This can make the material a better conductor. The material is either an N-type or a P-type, depending on whether it has added electrons or added holes.
LEDs are used for many different kinds of tasks. Most people are familiar with them on their digital clock or on another electronic display of some other type. When used in a larger collection they may make up a large TV screen or even provide the colors for a traffic signal. Think of light emitting diodes as very small “light bulbs.” They are more efficient because they don’t have a filament to burn out. When they are made as described above they provide their light due to the electrons moving in the semiconductor material.
When an LED is “on” the energy is produced by electrons that move to “holes” or “spaces” provided by proper doping and construction of the semiconductor material. The differences in light level and color come from the energy of the photons, the elementary particles that are the basic units of light.
LEDs were first used nearly 50 years ago. Many people at that time were interested and even amazed by the low-level red light of these early light emitting diodes. In the last couple of decades, developers have created LEDs that provide a wide range of colors. These newer versions are also much sharper and brighter than the original LEDs of the 1960s.
Light emitting diodes last longer than traditional light sources such as incandescent bulbs. They also use less energy and don’t give off the excess heat that is common with older forms of lighting. LEDs may be more expensive when original costs are compared to the classic forms of light bulbs. When designers put circuits together using light emitting diodes they have to be more precise with the amounts of current and heat, so that the LEDs work as they should.
Light emitting diodes also have what is called an efficient, fast switching rate. This means that they can change from “on” to “off” mode in a way that allows them to be used in crucial communications. All electricity is the result of electron movement. LEDs bring this operation to a small and very efficient level.
Category: Technology