LEDs: An In-Depth Look

LED–Light Emitting Diode

semi conductor light source

an optoelectronic

optoelectronics -> study and application of electronic devices that source, detect, and control light (gamma, X-rays, UV, IR)

When a light-emitting diode is switched on, electrons are able to recombine with holes within the device, releasing energy in the form of photons

recombine -> radiative recombination/spontaneous emission process by which a light source (ie electron) in an excited state undergoes a transition to the ground state and emits a photon

http://en.wikipedia.org/wiki/Radiative_recombination

holes -> more of a concept; describes the lack of an electron at a position where one could exist in an atom.

When an electron leaves a helium atom, it leaves an electron hole in its place. This causes the helium atom to become positively charged

http://en.wikipedia.org/wiki/Electron_hole

photon -> A quantum (bundle or packet) of electromagnetic energy (light)

http://www.pcmag.com/encyclopedia_term/0,2542,t=photon&i=49210,00.asp

referred to as electroluminescence

electroluminescence -> a material emits light in response to an electric charge passed through it.

the color of the light corresponds to the energy of the photon, and is determined by the energy gap of the semiconductor.

energy gap -> energy difference between the top of a valence band and the bottom of the conduction band

http://www.wordiq.com/definition/Band_gap

lower energy consumption, longer lifetime, smaller size, faster switching, greater durability and reliability than incandescent lights

better at placing light in a single direction