What is LED?
LEDs (light emitting diodes) are solid-state semiconductor devices that can convert electrical energy directly into light. The heart of a led is a semiconductor chip of which one side is attached on the top of an anvil that is the negative power lead and the other side is connected with a whisker to a positive power lead. It is the most important part of the LED and it is entirely encapsulated in an epoxy resin enclosure.
A semiconductor chip consists of two parts, one is called P-Type semiconductor where holes dominate the region, and the other part is N-type semiconductor where is dominate by electrons. When they are sandwiched together there is a PN junction in between. When an electric current is applied to the chip through the lead, electrons are pushed across the junction into the P region, there, electrons and holes meet and recombine, and then release energy in the form of photons of light. The wavelength of the light therefore its colour, depends on the materials forming the PN junction, which is, the materials used to make the LED chip.
Generally, LED chips are made from gallium-based crystals that contain one or more additional materials such as phosphor to produce a distinct colour.
Features and Benefits of LED
An LED is essentially a microscopic chip once encapsulated in an eposxy resin are extremely small and lightweight.
Low power consumption:
LED consume very little power, far less than a standard light bulbs leading to greatly reduced energy costs and extremely enhanced global energy savings. LEDs also require far less energy to manufacture than other light sources, reducing the enviromental impact of artificial lighting even further. Generally a LED is designed to operate at 2-3.6v, 0.02-0.03A Current which means a LED typically requires no more than 0.1w to operate.
LEDs are rugged solid state devices and are not susceptable to vibration suach as with incandescent filament based bulbs.
When operating at specified voltage, current, and within the specified environmental conditions, LEDs can enjoy a long life of up to 100,000 hours. A newer way to avaluate LED lifetime has been established and adopted which is based on lumens depreciation over time to determine the Mean Time Between Failure ( MTBF).
The LED-semi-conductor chip is completely embedded in an epoxy resin enclosure which is much more sturdy than traditional glass bulbs or fluorescent tubes. They are solid-state technology thus no loose and moving parts which makes the LEDs virtually indestructable.