Luminescent emitters

All light radiation that is not based on the temperature of a solid body is called Luminescence Radiation. Luminescence radiation is produced when electrons move from one energy level to another. The necessary energy can be applied to the luminescence radiator in the form of various excitation energies.

Radiation
Designation Excitation energy  
Electro luminescenence Electrical power Gas discharge, pn - transition
Photo luminescenence Electro-magnetic radiation UV-conversion with luminescent materials
Chemo- and
bio luminescenence		 Energy caused by chemical reactions Burning, oxidation, enzymatic reactions
Tribo luminescenence Mechanical power E.g., excitation of luminous effects in crystals through mechanical energy
Thermo luminescenence Thermal power E.g., excitation of luminous effects in crystals through heat
Radio luminescenence Radioactivity Aurora Borealis (polar aurora)

High-pressure discharge lamps and low-pressure sodium lamps are therefore luminescence radiators in which the excitation energy is supplied in the form of an electrical current. In contrast, the luminescence of low-pressure mercury lamps comes from radiation energy (UV radiation).
Technical innovations in the luminescence of semiconductor materials (LEDs) and plastics (organic LEDs) are already being put to practical use. For a long time, the options were restricted to yellow, green and red LEDs. Blue and white LEDs are now available. The luminous efficacy of the blue and white LEDs is comparable to that of thermal radiators.
 
As further developments are made, the luminous efficacy of these products will increase and this will revolutionise the lighting industry and lighting applications.

Light Generation

Basically, there are three ways in which electricity can be used to produce light: thermal radiation, low-pressure discharge and high-pressure discharge.

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