In chemistry, a luminophore (sometimes shortened to lumophore) is an

atom Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Only the most common variety of hydrogen has no neutrons. Every solid, liquid, gas ...

functional group In organic chemistry, a functional group is a substituent or moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions regardless of the res ...

in a

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one ele ...

that is responsible for its

luminescent Luminescence is spontaneous emission of light by a substance not resulting from heat; or "cold light". It is thus a form of cold-body radiation. It can be caused by chemical reactions, electrical energy, subatomic motions or stress on a crysta ...

properties. Luminophores can be either

organic Organic may refer to: * Organic, of or relating to an organism, a living entity * Organic, of or relating to an anatomical organ Chemistry * Organic matter, matter that has come from a once-living organism, is capable of decay or is the product o ...

inorganic In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemis ...

. Luminophores can be further classified as

fluorophore A fluorophore (or fluorochrome, similarly to a chromophore) is a fluorescent chemical compound that can re-emit light upon light excitation. Fluorophores typically contain several combined aromatic groups, or planar or cyclic molecules with ...

s or

phosphor A phosphor is a substance that exhibits the phenomenon of luminescence; it emits light when exposed to some type of radiant energy. The term is used both for fluorescent or phosphorescent substances which glow on exposure to ultraviolet or ...

s, depending on the nature of the

excited state In quantum mechanics, an excited state of a system (such as an atom, molecule or nucleus) is any quantum state of the system that has a higher energy than the ground state (that is, more energy than the absolute minimum). Excitation refers t ...

responsible for the emission of

photon A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are Massless particle, massless ...

s. However, some luminophores cannot be classified as being exclusively fluorophores or phosphors. Examples include transition-metal complexes such as

tris(bipyridine)ruthenium(II) chloride Tris(bipyridine)ruthenium(II) chloride is the chloride salt coordination complex with the formula u(bpy)3sup>2+ 2Cl−. This polypyridine complex is a red crystalline salt obtained as the hexahydrate, although all of the properties of interest a ...

, whose luminescence comes from an excited (nominally triplet) metal-to-ligand charge-transfer (MLCT) state, which is not a true triplet state in the strict sense of the definition; and colloidal

quantum dots Quantum dots (QDs) are semiconductor particles a few nanometres in size, having optical and electronic properties that differ from those of larger particles as a result of quantum mechanics. They are a central topic in nanotechnology. When the ...

, whose emissive state does not have either a purely singlet or triplet spin. Most luminophores consist of conjugated π systems or transition-metal complexes. There are also purely inorganic luminophores, such as

zinc sulfide Zinc sulfide (or zinc sulphide) is an inorganic compound with the chemical formula of ZnS. This is the main form of zinc found in nature, where it mainly occurs as the mineral sphalerite. Although this mineral is usually black because of various i ...

doped with

rare-earth metal The rare-earth elements (REE), also called the rare-earth metals or (in context) rare-earth oxides or sometimes the lanthanides (yttrium and scandium are usually included as rare earths), are a set of 17 nearly-indistinguishable lustrous silve ...

ions, rare-earth metal oxysulfides doped with other rare-earth metal ions,

yttrium oxide Yttrium oxide may refer to: * Yttrium(II) oxide, YO, a dark brown solid * Yttrium(III) oxide Yttrium oxide, also known as yttria, is Y2 O3. It is an air-stable, white solid substance. The thermal conductivity of yttrium oxide is 27 W/(m·K). ...

doped with rare-earth metal ions,

zinc orthosilicate Willemite is a zinc silicate mineral () and a minor ore of zinc. It is highly fluorescent (green) under shortwave ultraviolet light. It occurs in a variety of colors in daylight, in fibrous masses and apple-green gemmy masses. Troostite is a ...

doped with manganese ions, etc. Luminophores can be observed in action in fluorescent lights, television screens, computer monitor screens,

organic light-emitting diode An organic light-emitting diode (OLED or organic LED), also known as organic electroluminescent (organic EL) diode, is a light-emitting diode (LED) in which the emissive electroluminescent layer is a film of organic compound that emits light ...

s and

bioluminescence Bioluminescence is the production and emission of light by living organisms. It is a form of chemiluminescence. Bioluminescence occurs widely in marine vertebrates and invertebrates, as well as in some fungi, microorganisms including some ...

. The correct, textbook terminology is ''luminophore'', not ''lumophore'', although the latter term has been frequently used in the chemical literature.

References

{{reflist, refs= {{Citation , first1 = Larry J. , last1 = Kricka , title = Optical Methods: A Guide to the "Escences" , publisher = American Association for Clinical Chemistry , page = 110 , year = 2003 , isbn = 1890883913 , url = https://books.google.com/books?id=q8aV3mAJFZgC&pg=PA110 , postscript= . {{Citation , first1 = Andrei , last1 = Dragan , title = Organic Luminophores , publisher = ChemPubSoc Europe , year = 2017 , url = https://www.chemistryviews.org/details/ezine/10483262/Organic_Luminophores.html , postscript= . Luminescence Chemical compounds

See also

References