Luminescence

right|thumb|Luminol reacting with haemoglobin is a familiar demonstration of [[chemiluminescence.]] thumb|UV-induced photoluminescence used in microbiological diagnostics.

thumb|Phosphorescent bird figure thumb|Phosphorescent, europium-doped, [[strontium silicate-aluminate oxide powder under visible light, fluorescing/phosphorescing under long-wave UV light, and persistently phosphorescing in total darkness]]

thumb|right|A chemoluminescent reaction in an Erlenmeyer flask

thumbnail|Views of a liquid crystal display, both with electroluminescent backlight switched on (top) and switched off (bottom) Electroluminescence (EL) is an optical and electrical phenomenon, in which a material emits light in response to the passage of an electric current or to a strong electric field. This is distinct from black body light emission resulting from heat (incandescence), illumination by light (photoluminescence), chemical reactions (chemiluminescence), reactions in a liquid (electrochemiluminescence), sound (sonoluminescence), or other mechanical action (mechanoluminescence),

chemical compound

thumb|Fluorescence|Fluorescent solutions under UV light. Absorbed photons are rapidly re-emitted under longer electromagnetic wavelengths.

right|thumb|Single-bubble sonoluminescence – a single, cavitating bubble Sonoluminescence is luminescence induced by sound waves, such as in the emission of light from imploding bubbles in a liquid when excited by sound. Sonoluminescence is sometimes considered a kind of mechanoluminescence. However, mechanoluminescence is typically defined as pertaining to solids, while sonoluminescence usually pertains to liquids. The related terms acoustoluminescence and sonotriboluminescence have been used to describe sound-induced luminescence in solids (e.g., crystals suspended in slurries).

thumb|Thermoluminescence of fluorite. thumb|Figure 1: Three stages of thermoluminescence as outlined by Aitken (1985, 1998) and applied to a quartz grain (Keizars, 2008b). thumb|Figure 2: The process of recharging and discharging thermoluminescent signal, as applied to beach sands. (modified from Aitken, 1998; Keizars, 2008). thumb|Figure 3: Thermoluminescence signature lost during migration of two sand grain sizes (Keizars, 2008). thumb|Figure 4: Illustrated method of passively monitoring sand input (Keizars, 2003).

thumb|right|Triboluminescence of nicotine -salicylate Triboluminescence is a phenomenon in which light is generated when a material is mechanically pulled apart, ripped, scratched, crushed, or rubbed (see tribology). The phenomenon is not fully understood but appears in most cases to be caused by the separation and reunification of static electric charges, see also triboelectric effect. The term comes from the Greek τρίβειν ("to rub"; see tribology) and the Latin lumen (light). Triboluminescence can be observed when breaking sugar crystals and peeling adhesive tapes.

thumb|Example of phosphorescence thumb|Monochrome monitor thumb|Aperture grille CRT phosphors

self-contained, short-term light-source

thumb|Blacklight fluorescent tubes. The violet glow of a blacklight is not the UV light itself, but visible light that escapes being filtered out by the filter material in the glass envelope.

thumb|right|300px|Radioluminescent tritium vial used as a light source. It consists of a sealed glass tube containing radioactive tritium gas, whose inner surfaces are coated with a [[phosphor.]]

beam of positive rays that are created by certain types of gas discharge tubes

thumb|Color cathodoluminescence of a diamond in Scanning electron microscope|SEM, real colors

thumb|A fluorophore-labeled human cell

radiometric tool for geochronology

blue fluorescent dye used to enhance apparent brightness of white paper, fabric, and plastics

'(E)-Stilbene, commonly known as trans-stilbene', is an organic compound represented by the condensed structural formula CHCH=CHCH. Classified as a diarylethene, it features a central ethylene moiety with one phenyl group substituent on each end of the carbon–carbon double bond. It has an (E) stereochemistry, meaning that the phenyl groups are located on opposite sides of the double bond, the opposite of its geometric isomer, cis-stilbene. Trans-stilbene occurs as a white crystalline solid at room temperature and is highly soluble in organic solvents. It can be converted to cis-stilbene

Electrochemiluminescence or electrogenerated chemiluminescence (ECL) is a kind of luminescence produced during electrochemical reactions in solutions. In electrogenerated chemiluminescence, electrochemically generated intermediates undergo a highly exergonic reaction to produce an electronically excited state that then emits light upon relaxation to a lower-level state. This wavelength of the emitted photon of light corresponds to the energy gap between these two states. ECL excitation can be caused by energetic electron transfer (redox) reactions of electrogenerated species. Such luminescence

'(Z)-Stilbene' is a diarylethene, that is, a hydrocarbon consisting of a cis ethene double bond substituted with a phenyl group on both carbon atoms of the double bond. The name stilbene was derived from the Greek word , which means shining.

chemical compound

In chemistry and materials science, a luminophore is the part of a molecule, coordination complex, or solid-state material that is responsible for its luminescence (light emission following excitation). In molecular photochemistry, the closely related IUPAC-recommended term lumiphore refers to "a part of a molecular entity (or atom or group of atoms) in which electronic excitation associated with a given emission band is approximately localized", by analogy with chromophore for absorption. In practice, the term luminophore is widely used across chemistry, physics, and engineering literature fo

Paint glowing in the dark

law of photochemistry

electrochemical processes involving photons and the emission or absorption of light

Candoluminescence is the light given off by certain materials at elevated temperatures (usually when exposed to a flame) that has an intensity at some wavelengths which can, through chemical action in flames, be higher than the blackbody emission expected from incandescence at the same temperature. The phenomenon is notable in certain transition-metal and rare-earth oxide materials (ceramics) such as zinc oxide, cerium(IV) oxide and thorium dioxide.

display made with electroluminescent material

capacitive light source in the form of a wire

thumb|right|250px|The Becquerel phosphoroscope (1873-1874) A phosphoroscope is piece of experimental equipment devised in 1857 by physicist A. E. Becquerel to measure how long it takes a phosphorescent material to stop glowing after it has been excited.

luminescent phenomenon discovered by Ben Zhong Tang et al. in 2001

Mechanoluminescence is light emission resulting from any mechanical action on a solid. Fractoluminescence is caused by stress that results in the formation of fractures, that in turn yield light. Piezoluminescence is caused by pressure that results in elastic deformation and large polarization from the piezoelectric effect. Triboluminescence is nominally caused by rubbing, but sometimes occurs because of resulting fractoluminescence. It is often used as a synonym.

Crystalloluminescence is the effect of luminescence produced during crystallization, specifically during nucleation. The phenomenon was first reported in the 1800s from the rapid crystallization of potassium sulfate from an aqueous solution.

thumb|Luminescence material with different solvent under UV light Piezoluminescence is a form of luminescence created by pressure upon certain solids. This phenomenon is characterized by recombination processes involving electrons, holes, and impurity ion centres. Some piezoelectric crystals give off a certain amount of piezoluminescence when under pressure. Irradiated salts, such as NaCl, KCl, KBr, and polycrystalline chips of LiF (TLD-100), have been found to exhibit piezoluminescent properties. It has also been discovered that ferroelectric polymers exhibit piezoluminescence upon the applic