Three decades ago, LEDs were only really known for being the power indicators on electronic devices, as they were too weak to be of much use elsewhere. Today, however, LED is leading the way in the fight to produce increasingly efficient lighting by dramatically reducing energy consumption.
The high-brightness blue LED was introduced in 1993. Twenty times brighter than its green or red predecessors, this was the long-awaited enabler of white LED light. Then, as now, white LED light was produced by blending red, green, and blue light or by using a blue LED with a yellow phosphor. From this point on LED bulbs started their journey to take over the world of lighting.
All very well, but what is an LED?
The real science bit…
A Light Emitting Diode (LED) is a device that allows electrical current to flow in only one direction. It includes two conductive materials, placed in contact with each other. Electricity is applied to the diode so that atoms in one material are excited to a higher energy level. That energy is then released in the form of electrons into the second material, and this release of energy creates light.
How does this differ from traditional lighting?
Traditional incandescent lighting produces light directly by heat. A thin tungsten filament is warmed to about 2500°C by an electric current. Filament bulbs use 90% of their energy in maintaining this extreme temperature.