More and more households are using LED light bulbs due to improved efficiency, reliability, and now a more affordable cost over their incandescent cousins. With droves of scientists researching in the area of LED and producing new developments, these bulbs are beginning to become the new norm.
Let’s take a look at the journey the LED bulb has gone though thus far.
This from CNET:
LEDs were first developed early in the last century, when a researcher noticed how applying a current to a certain type of crystal diode (an electrical component that only allows electricity to flow in one direction) made it give off a faint light. The material was not heating up; it was emitting light through another unknown method. This phenomenon (later called electroluminescence) remained a scientific oddity without much practical use until the 1950s, when companies started harnessing it to produce LED lights.
The LED has gone though many transitions since its discovery. LEDs started out being made from a compound called gallium arsenide (GaAs). Then, similar materials were used to produce LEDs that gave off a red and yellow light. This made it possible to create bigger and brighter LEDs.
The issue? This process allows the bulbs to emit only one single frequency/color. In order to produce light that is the same white of the sun, the bulb needs to produce a range of frequencies.
Recently, three scientists figured out a way to make blue LEDs. This was discovered by Isamu Akasaki, Hiroshi Amano, and Shuji Nakamura, for which the 2014 Nobel Prize in Physics was won.
This from CNET:
The blue LED that their process allows is the holy grail of LEDs, because blue light can be converted to other colors by phosphors, chemicals that absorb light and then give it off at a different, higher frequency. There are plenty of phosphors that can convert blue light to green and red, so if you combine a blue LED with some of these phosphors, you get white light, and a white LED.
This discovery lead to the creation of a light bulb that is more efficient than the old incandescent one.
The old bulb used 60 watts of energy to illuminate a room. The LED can produce the same amount of light using less than 10 watts. And because there is no heated filament required, the bulb last much longer.
While the bulbs are still not perfect, the future looks promising. It is possible that the LED will eventually outpace the incandescent completely.
Head over to our Digital Library to check out the latest developments in LED. While you’re there, make sure to sign up for our e-Alerts so you don’t miss the latest breakthroughs in electrochemical and solid state science.