What are LEDs?
The manufacturing process of LEDs is known as epitaxy, in which crystalline layers of different semiconductor material are grown on top of one another. Advances in epitaxial crystal growth processes have enabled the use of LED materials for colors that previously could not be made with high enough purity and structural precision.
Recent breakthroughs in the technique of chemical vapor deposition from metal organic precursors enable the cost-effective production of nitrides of the group III-metals from the periodic table including aluminum gallium indium nitrides. Highly efficient InGaN blue LEDs result from this process.
About 30 percent of the light generated inside the chip makes it way out of the brightest LEDs. Semiconductor materials have very high indices of refraction and can trap a great deal of light when configured in a square chip. An epoxy encapsulant around the LED chip reduces the refractive index mismatch and allows more light to be emitted.
For some LEDs, the light escaping the chip (extraction efficiency) can be 4 percent or lower. Transparent substrates and thick semiconductor layers increase the extraction efficiency. Making LED chips more spherical, which is now not practical for mass production, could also significantly increase extraction efficiency.
About LED bulbs
LED bulbs were developed in the 1960s, recent advancements have developed LED bulbs into a bright, efficient, long lasting and purely electronic source of lighting that produces very little waste.
LED’s function on a polar mechanism, the amount of light emitted is based on the shape and curvature of the housing surrounding the lens.
LED bulbs are therefore measured by the radius of curvature (mm).
LED bulbs are being used for their energy efficiency and overall cost effectiveness, they last longer and are 5-6 times less power consumptive that comparable incandescent bulbs.
LED or Light Emitting Diode’s are diodes that give off light.
LED’s transports electricity into light in the absolute most efficient way.
LED bulbs transfer 100% of the energy into light versus an incandescent light bulb which only transfers 10-20% of the energy into light.
LED’s have made large improvements since the 1970’s, the biggest problem currently, is the price of LED’s.