Phosphors and Fluorescent Powders

Synonyms

Luminescent materials

Definition

Phosphor (fluorescent powder) is a kind of inorganic materials which absorbs the energy from electrons, photons, or even other forms of microscopic particles and converts it into visible light. Phosphor (fluorescent powder) has a history of about 100 years and today plays one of the key roles in lighting, display, and imaging. So far there are varieties of phosphors finding their applications in cathode-ray tubes (CRTs), fluorescent lamps, x-ray films, plasma display panels (PDPs), and recently developed white light-emitting diodes (w-LEDs).

The Mechanism of Luminescence

Although phosphors are available in diversity, the mechanisms of luminescence in them are similar, including the following primary items:

• Transitions of rare-earth ions and transition metal ions

• Crystal field splitting and nephelauxetic effect

• Energy transfer

Transitions of Rare-Earth Ions and Transition Metal Ions

Essentially, luminescence of phosphors is a process of electron...