Speaking of LEDs, probably one would have heard and found that everywhere, the computers, the cell phones, the traffic lights, the flat screens and so on. LED’s everywhere in our daily life, providing indications . However, with some exceptions, the initial intention of LEDs was for indication but not illumination, at the very beginning, LED’s had nothing to do with general lighting.
New developments, however, are starting to bring SSL (solid-state lighting) into our homes in the near future. In fact, nowadays, you will find there are many on-line shops that are already selling some
LED lights products such as MR16 and GU10 spotlights and
LED bulbs.
An LED, originally referred to Light Emitting Diode, is one type of circuit element emitting light when electricity moves through it in the specific direction. Just like a normal diode, electrical current will be blocked when it tried to pass through the opposite direction of the diode. With a positive voltage to the positive siide of an LED, the electrons that must jump down in energy when they cross the diode, in this process, the electron will be emitting the lost energy as light – that is the principle how LEDs emit light. This light is at one specific frequency, and the frequency will depending characteristics of the materials being used. When generating white light that may be applied to illumination , it will need a mixing up of many different clolours – something LEDs did not seemed to be able to accomplish in the past.
Red light was the very first visible light LED to be created, in 1962, followed by yellow and green. Later (actually about 30 years later), in early 1990′s, blue-spectrum LED’s were invented – an enormous advance in usefulness, due to the fact blue light could be joined with red and green to produce white light. Nevertheless, this method was not efficient, and corporations were battling to develop a single diode that is able to generate white light by itself. Then, in 1993, a corporation referred to as Nichia developed the first white LED utilizing a blue LED with a phosphor coating. The coating was the secret to success – it provided sufficient shifting of the light wavelength coming from the diode itself to generate white colored light.
So why, aren’t we using
LED lights (in most of our homes) – significantly more efficient than either incandescent or fluorescent lights – to our homes, offices and warehouses? The primary challenge, clearly, is cost. Current white LED’s substrate made up of sapphire additional mirroring layer to reflect light which will otherwise be lost. As a consequence, LED lights that are available on the market cost somewhere around 10, 20 or even more times than traditional lights, too much for the average consumer.
Researchers have realized one way of significantly keeping down the expense of white LEDs by reducing the expensive layer of sapphire. As an alternative solution, they used silicon as the substrate and zirconium nitride as the reflector. This had never been carried out before, primarily because silicon reacts with zirconium nitride and changes its properties. The study solved this by locating a layer of aluminum nitride between the silicon and zirconium nitride.
LED lighting carries various benefits over traditional lighting, most especially in efficiency. LED’s are at the same time more durable than incandescent or compact fluorescent lights, and have the advantage of being without having mercury – a chemical discovered in compact fluorescent lights that makes them difficult to get rid of.
The industry is booming, it is expected that LED lights will be adopted widely in homes and office in the near future (some expect it will be 5-10 years). There are still technologies issues, but the LED industry may finally find its way.
