A
phosphor, most generally, is a substance that exhibits the
phenomenonAn optical phenomenon is any observable event that results from the interaction of light and matter. See also list of optical topics and optics. A mirage is an example of an optical phenomenon....
of
luminescenceLuminescence is emission of light by a substance not resulting from heat; it is thus a form of cold body radiation. It can be caused by chemical reactions, electrical energy, subatomic motions, or stress on a crystal. This distinguishes luminescence from incandescence, which is light emitted by a...
. Somewhat confusingly, this includes both
phosphorescentPhosphorescence is a specific type of photoluminescence related to fluorescence. Unlike fluorescence, a phosphorescent material does not immediately re-emit the radiation it absorbs. The slower time scales of the re-emission are associated with "forbidden" energy state transitions in quantum...
materials, which show a slow decay in brightness (>1ms), and
fluorescentFluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation of a different wavelength. It is a form of luminescence. In most cases, emitted light has a longer wavelength, and therefore lower energy, than the absorbed radiation...
materials, where the emission decay takes place over tens of nanoseconds. Phosphorescent materials are known for their use in radar screens and glow-in-the-dark toys, whereas fluorescent materials are common in CRT and plasma video display screens, sensors, and white LEDs.
Phosphors are often
transition metalThe term transition metal has two possible meanings:*The IUPAC definition states that a transition metal is "an element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell." Group 12 elements are not transition metals in this definition.*Some...
compounds or
rare earthAs defined by IUPAC, rare earth elements or rare earth metals are a set of seventeen chemical elements in the periodic table, specifically the fifteen lanthanides plus scandium and yttrium...
compounds of various types. The most common uses of phosphors are in
CRTThe cathode ray tube is a vacuum tube containing an electron gun and a fluorescent screen used to view images. It has a means to accelerate and deflect the electron beam onto the fluorescent screen to create the images. The image may represent electrical waveforms , pictures , radar targets and...
displays and fluorescent lights. CRT phosphors were standardized beginning around
World War IIWorld War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
and designated by the letter "P" followed by a number.
PhosphorusPhosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...
, the chemical element named for its light-emitting behavior, emits light due to chemiluminescence, not phosphorescence.
Principles
A material can emit light either through
incandescenceIncandescence is the emission of light from a hot body as a result of its temperature. The term derives from the Latin verb incandescere, to glow white....
, where all atoms radiate, or by
luminescenceLuminescence is emission of light by a substance not resulting from heat; it is thus a form of cold body radiation. It can be caused by chemical reactions, electrical energy, subatomic motions, or stress on a crystal. This distinguishes luminescence from incandescence, which is light emitted by a...
, where only a small fraction of atoms, called
emission centers or
luminescence centers, emit light. In inorganic phosphors, these inhomogeneities in the crystal structure are created usually by addition of a trace amount of
dopantA dopant, also called a doping agent, is a trace impurity element that is inserted into a substance in order to alter the electrical properties or the optical properties of the substance. In the case of crystalline substances, the atoms of the dopant very commonly take the place of elements that...
s, impurities called
activatorsIn phosphors and scintillators, the activator is the element added as dopant to the crystal of the material to create desired type of nonhomogeneities....
. (In rare cases
dislocationIn materials science, a dislocation is a crystallographic defect, or irregularity, within a crystal structure. The presence of dislocations strongly influences many of the properties of materials...
s or other crystal defects can play the role of the impurity.) The wavelength emitted by the emission center is dependent on the atom itself, and on the surrounding crystal structure.
The scintillation process in inorganic materials is due to the
electronic band structureIn solid-state physics, the electronic band structure of a solid describes those ranges of energy an electron is "forbidden" or "allowed" to have. Band structure derives from the diffraction of the quantum mechanical electron waves in a periodic crystal lattice with a specific crystal system and...
found in the
crystalA crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...
s. An incoming particle can excite an electron from the
valence bandIn solids, the valence band is the highest range of electron energies in which electrons are normally present at absolute zero temperature....
to either the
conduction bandIn the solid-state physics field of semiconductors and insulators, the conduction band is the range of electron energies, higher than that of the valence band, sufficient to free an electron from binding with its individual atom and allow it to move freely within the atomic lattice of the material...
or the
excitonAn exciton is a bound state of an electron and hole which are attracted to each other by the electrostatic Coulomb force. It is an electrically neutral quasiparticle that exists in insulators, semiconductors and some liquids...
band (located just below the conduction band and separated from the valence band by an energy gap). This leaves an associated
holeAn electron hole is the conceptual and mathematical opposite of an electron, useful in the study of physics, chemistry, and electrical engineering. The concept describes the lack of an electron at a position where one could exist in an atom or atomic lattice...
behind, in the valence band. Impurities create electronic levels in the forbidden gap. The excitons are loosely bound electron-hole pairs that wander through the crystal lattice until they are captured as a whole by impurity centers. The latter then rapidly de-excite by emitting scintillation light (fast component). In case of inorganic
scintillatorA scintillator is a special material, which exhibits scintillation—the property of luminescence when excited by ionizing radiation. Luminescent materials, when struck by an incoming particle, absorb its energy and scintillate, i.e., reemit the absorbed energy in the form of light...
s, the activator impurities are typically chosen so that the emitted light is in the visible range or near-UV where
photomultiplierPhotomultiplier tubes , members of the class of vacuum tubes, and more specifically phototubes, are extremely sensitive detectors of light in the ultraviolet, visible, and near-infrared ranges of the electromagnetic spectrum...
s are effective. The holes associated with electrons in the conduction band are independent from the latter. Those holes and electrons are captured successively by impurity centers exciting certain metastable states not accessible to the excitons. The delayed de-excitation of those metastable impurity states, slowed down by reliance on the low-probability
forbidden mechanismIn physics, a forbidden mechanism or forbidden line is a spectral line emitted by atoms undergoing nominally "forbidden" energy transitions not normally allowed by the selection rules of quantum mechanics. In formal physics, this means that the process cannot proceed via the most efficient route...
, again results in light emission (slow component).
Phosphor degradation
Many phosphors tend to lose efficiency gradually by several mechanisms. The activators can undergo change of
valenceIn chemistry, valence, also known as valency or valence number, is a measure of the number of bonds formed by an atom of a given element. "Valence" can be defined as the number of valence bonds...
(usually oxidation), the crystal lattice degrades, atoms - often the activators - diffuse through the material, the surface undergoes chemical reactions with the environment with consequent loss of efficiency or buildup of a layer absorbing either the exciting or the radiated energy, etc.
The degradation of electroluminescent devices depends on frequency of driving current, the luminance level, and temperature; moisture impairs phosphor lifetime very noticeably as well.
Examples:
- BaMgAl10O17:Eu2+ (BAM), a plasma display
A plasma display panel is a type of flat panel display common to large TV displays or larger. They are called "plasma" displays because the technology utilizes small cells containing electrically charged ionized gases, or what are in essence chambers more commonly known as fluorescent...
phosphor, undergoes oxidation of the dopant during baking. Three mechanisms are involved; absorption of oxygen atoms into oxygen vacancies on the crystal surface, diffusionMolecular diffusion, often called simply diffusion, is the thermal motion of all particles at temperatures above absolute zero. The rate of this movement is a function of temperature, viscosity of the fluid and the size of the particles...
of Eu(II) along the conductive layer, and electron transferElectron transfer is the process by which an electron moves from an atom or a chemical species to another atom or chemical species...
from Eu(II) to adsorbed oxygen atoms, leading to formation of Eu(III) with corresponding loss of emissivity. Thin coating of aluminium phosphateAluminium phosphate is a chemical compound. It is used in cake mixes and in some baking powders as a leavening agent to help baked goods rise. Medicinally it is used as adsorbent for toxoid.-Uses:...
or lanthanum(III) phosphate is effective in creation a barrier layer blocking access of oxygen to the BAM phosphor, for the cost of reduction of phosphor efficiency. Addition of hydrogenHydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
, acting as a reducing agentA reducing agent is the element or compound in a reduction-oxidation reaction that donates an electron to another species; however, since the reducer loses an electron we say it is "oxidized"...
, to argonArgon is a chemical element represented by the symbol Ar. Argon has atomic number 18 and is the third element in group 18 of the periodic table . Argon is the third most common gas in the Earth's atmosphere, at 0.93%, making it more common than carbon dioxide...
in the plasma displays significantly extends the lifetime of BAM:Eu2+ phosphor, by reducing the Eu(III) atoms back to Eu(II).
- Y2O3:Eu phosphors under electron bombardment in presence of oxygen form a non-phosphorescent layer on the surface, where electron-hole pairs recombine
In the solid state physics of semiconductors, carrier generation and recombination are processes by which mobile charge carriers are created and eliminated. Carrier generation and recombination processes are fundamental to the operation of many optoelectronic semiconductor devices, such as...
nonradiatively via surface states.
- ZnS:Mn, used in AC thin film electroluminescent (ACTFEL) devices degrades mainly due to formation of deep electron traps, by reaction of water molecules with the dopant; the traps act as centers for nonradiative recombination. The traps also damage the crystal lattice. Phosphor aging leads to decreased brightness and elevated threshold voltage.
- ZnS-based phosphors in CRT
The cathode ray tube is a vacuum tube containing an electron gun and a fluorescent screen used to view images. It has a means to accelerate and deflect the electron beam onto the fluorescent screen to create the images. The image may represent electrical waveforms , pictures , radar targets and...
s and FEDA field emission display is a display technology that incorporates flat panel display technology that uses large-area field electron emission sources to provide electrons that strike colored phosphor to produce a color image as a electronic visual display...
s degrade by surface excitation, coulombic damage, build-up of electric charge, and thermal quenching. Electron-stimulated reactions of the surface are directly correlated to loss of brightness. The electrons dissociate impurities in the environment, the reactive oxygen speciesReactive oxygen species are chemically reactive molecules containing oxygen. Examples include oxygen ions and peroxides. Reactive oxygen species are highly reactive due to the presence of unpaired valence shell electrons....
then attack the surface and form carbon monoxideCarbon monoxide , also called carbonous oxide, is a colorless, odorless, and tasteless gas that is slightly lighter than air. It is highly toxic to humans and animals in higher quantities, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal...
and carbon dioxideCarbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
with traces of carbonCarbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
, and nonradiative zinc oxideZinc oxide is an inorganic compound with the formula ZnO. It is a white powder that is insoluble in water. The powder is widely used as an additive into numerous materials and products including plastics, ceramics, glass, cement, rubber , lubricants, paints, ointments, adhesives, sealants,...
and zinc sulfateZinc sulfate is the inorganic compound with the formula ZnSO4 as well as any of three hydrates. It was historically known as "white vitriol". It is a colorless solid that is a common source of soluble zinc ions.-Production and reactivity:...
on the surface; the reactive hydrogenHydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
removes sulfurSulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...
from the surface as hydrogen sulfideHydrogen sulfide is the chemical compound with the formula . It is a colorless, very poisonous, flammable gas with the characteristic foul odor of expired eggs perceptible at concentrations as low as 0.00047 parts per million...
, forming nonradiative layer of metallic zincZinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
. Sulfur can be also removed as sulfur oxideSulfur oxide refers to one or more of the following:* Lower sulfur oxides * Sulfur monoxide * Sulfur dioxide * Sulfur trioxide *Higher sulfur oxides Sulfur oxide (SOx) refers to one or more of the following:* Lower sulfur oxides (SnO, S7O2 and S6O2)* Sulfur monoxide (SO)* Sulfur dioxide (SO2)*...
s.
- ZnS and CdS phosphors degrade by reduction of the metal ions by captured electrons. The Me2+ ions are reduced to Me+; two Me+ then exchange an electron and become one Me2+ and one neutral Me atom. The reduced metal can be observed as a visible darkening of the phosphor layer. The darkening (and the brightness loss) is proportional to the phosphor's exposition to electrons, and can be observed on some CRT screens that displayed the same image (e.g. a terminal login screen) for prolonged periods.
Materials
Phosphors are usually made from a suitable host material with an added
activatorIn phosphors and scintillators, the activator is the element added as dopant to the crystal of the material to create desired type of nonhomogeneities....
. The best known type is a copper-activated zinc sulfide and the silver-activated zinc sulfide (
zinc sulfide silver).
The host materials are typically
oxideAn oxide is a chemical compound that contains at least one oxygen atom in its chemical formula. Metal oxides typically contain an anion of oxygen in the oxidation state of −2....
s,
nitrideIn chemistry, a nitride is a compound of nitrogen where nitrogen has a formal oxidation state of −3. Nitrides are a large class of compounds with a wide range of properties and applications....
s and oxynitrides,
sulfideA sulfide is an anion of sulfur in its lowest oxidation state of 2-. Sulfide is also a slightly archaic term for thioethers, a common type of organosulfur compound that are well known for their bad odors.- Properties :...
s,
selenideA selenide is a chemical compound in which selenium serves as an anion with oxidation number of −2 , much as sulfur does in a sulfide. The chemistry of the selenides and sulfides are similar....
s,
halideA halide is a binary compound, of which one part is a halogen atom and the other part is an element or radical that is less electronegative than the halogen, to make a fluoride, chloride, bromide, iodide, or astatide compound. Many salts are halides...
s or
silicateA silicate is a compound containing a silicon bearing anion. The great majority of silicates are oxides, but hexafluorosilicate and other anions are also included. This article focuses mainly on the Si-O anions. Silicates comprise the majority of the earth's crust, as well as the other...
s of
zincZinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
,
cadmiumCadmium is a chemical element with the symbol Cd and atomic number 48. This soft, bluish-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Similar to zinc, it prefers oxidation state +2 in most of its compounds and similar to mercury it shows a low...
,
manganeseManganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...
,
aluminiumAluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....
,
siliconSilicon is a chemical element with the symbol Si and atomic number 14. A tetravalent metalloid, it is less reactive than its chemical analog carbon, the nonmetal directly above it in the periodic table, but more reactive than germanium, the metalloid directly below it in the table...
, or various
rare earthAs defined by IUPAC, rare earth elements or rare earth metals are a set of seventeen chemical elements in the periodic table, specifically the fifteen lanthanides plus scandium and yttrium...
metals. The activators prolong the emission time (afterglow). In turn, other materials (such as
nickelNickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile...
) can be used to quench the afterglow and shorten the decay part of the phosphor emission characteristics.
Many phosphor powders are produced in low-temperature processes, such as sol-gel and usually require post-annealing at temperatures of ~1000 °C, which is undesirable for many applications. However, proper optimization of the growth process allows to avoid the annealing.
Phosphors used for
fluorescent lampA fluorescent lamp or fluorescent tube is a gas-discharge lamp that uses electricity to excite mercury vapor. The excited mercury atoms produce short-wave ultraviolet light that then causes a phosphor to fluoresce, producing visible light. A fluorescent lamp converts electrical power into useful...
s require a multi-step production process, with details that vary depending on the particular phosphor. Bulk material must be milled to obtain a desired particle size range, since large particles produce a poor quality lamp coating and small particles produce less light and degrade more quickly. During the firing of the phosphor, process conditions must be controlled to prevent oxidation of the phosphor activators or
contaminationContamination is the presence of a minor and unwanted constituent in material, physical body, natural environment, at a workplace, etc.-Specifics:"Contamination" also has more specific meanings in science:...
from the process vessels. After milling the phosphor may be washed to remove minor excess of activator elements. Volatile elements must not be allowed to escape during processing. Lamp manufacturers have changed composition of phosphors to eliminate some toxic elements, such as
berylliumBeryllium is the chemical element with the symbol Be and atomic number 4. It is a divalent element which occurs naturally only in combination with other elements in minerals. Notable gemstones which contain beryllium include beryl and chrysoberyl...
,
cadmiumCadmium is a chemical element with the symbol Cd and atomic number 48. This soft, bluish-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Similar to zinc, it prefers oxidation state +2 in most of its compounds and similar to mercury it shows a low...
, or
thalliumThallium is a chemical element with the symbol Tl and atomic number 81. This soft gray poor metal resembles tin but discolors when exposed to air. The two chemists William Crookes and Claude-Auguste Lamy discovered thallium independently in 1861 by the newly developed method of flame spectroscopy...
, formerly used.
The commonly quoted parameters for phosphors are the
wavelengthIn physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...
of emission maximum (in nanometers, or alternatively
color temperatureColor temperature is a characteristic of visible light that has important applications in lighting, photography, videography, publishing, manufacturing, astrophysics, and other fields. The color temperature of a light source is the temperature of an ideal black-body radiator that radiates light of...
in kelvins for white blends), the peak width (in nanometers at 50% of intensity), and decay time (in seconds).
Lighting
Phosphor layers provide most of the light produced by
fluorescent lampA fluorescent lamp or fluorescent tube is a gas-discharge lamp that uses electricity to excite mercury vapor. The excited mercury atoms produce short-wave ultraviolet light that then causes a phosphor to fluoresce, producing visible light. A fluorescent lamp converts electrical power into useful...
s, and are also used to improve the balance of light produced by
metal halide lampMetal-halide lamps, a member of the high-intensity discharge family of lamps, produce high light output for their size, making them a compact, powerful, and efficient light source. By adding rare earth metal salts to the mercury vapor lamp, improved luminous efficacy and light color is obtained...
s. Various
neon signNeon signs are made using electrified, luminous tube lights that contain rarefied neon or other gases. They are the most common use for neon lighting, which was first demonstrated in a modern form in December, 1910 by Georges Claude at the Paris Motor Show. While they are used worldwide, neon signs...
s use phosphor layers to produce different colors of light.
Electroluminescent displayElectroluminescent Displays are a type of Flat panel display created by sandwiching a layer of electroluminescent material such as GaAs between two layers of conductors. When current flows, the layer of material emits radiation in the form of visible light...
s found, for example, in aircraft instrument panels, use a phosphor layer to produce glare-free illumination or as numeric and graphic display devices.
Phosphor thermometry
Phosphor thermometryPhosphor thermometry is an optical method for surface temperature measurement. The method exploits luminescence emitted by phosphor material. Phosphors are fine white or pastel-colored inorganic powders which may be stimulated by any of a variety of means to luminesce, i.e. emit light...
is a temperature measurement approach that uses the temperature dependence of certain phosphors for this purpose. For this, a phosphor coating is applied to a surface of interest and, usually, the decay time is the emission parameter that indicates temperature. Because the illumination and detection optics can be situated remotely, the method may be used for moving surfaces such as high speed motor surfaces. Also, phosphor may be applied to the end of an optical fiber as an optical analog of a thermocouple.
Glow-in-the-dark toys
- Calcium sulfide
Calcium sulfide is the chemical compound with the formula CaS. This white material crystallizes in cubes like rock salt. CaS has been studied as a component in a process that would recycle gypsum, a product of flue gas desulfurization...
with strontium sulfideStrontium sulfide is used as an additive in fireworks because it creates a bright red flame when burnt. It is also used in depilatories and luminous paints, being a phosphor.-External links:*...
with bismuthBismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a trivalent poor metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally uncombined, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead...
as activator, (Ca,Sr)S:Bi, yields blue light with glow times up to 12 hours, red and orange are modifications of the zinc sulfide formula. Red color can be obtained from strontium sulfide.
- Zinc sulfide
Zinc sulfide is a inorganic compound with the formula ZnS. ZnS is the main form of zinc in nature, where it mainly occurs as the mineral sphalerite...
with about 5 ppm of a copperCopper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
activator is the most common phosphor for the glow-in-the-dark toys and items. It is also called GS phosphor.
- Mix of zinc sulfide and cadmium sulfide
Cadmium sulfide is the inorganic compound with the formula CdS. Cadmium sulfide is a yellow solid. It occurs in nature with two different crystal structures as the rare minerals greenockite and hawleyite, but is more prevalent as an impurity substituent in the similarly structured zinc ores...
emit color depending on their ratio; increasing of the CdS content shifts the output color towards longer wavelengths; its persistence ranges between 1–10 hours.
- Strontium aluminate
Strontium aluminate is a solid odorless, nonflammable, pale yellow powder, heavier than water. It is chemically and biologically inert. When activated with a suitable dopant , it acts as a photoluminescent phosphor with long persistence of phosphorescence...
activated by europiumEuropium is a chemical element with the symbol Eu and atomic number 63. It is named after the continent of Europe. It is a moderately hard silvery metal which readily oxidizes in air and water...
, SrAl2O4:Eu(II):Dy(III), is a newer material with higher brightness and significantly longer glow persistence; it produces green and aqua hues, where green gives the highest brightness and aqua the longest glow time. SrAl2O4:Eu:Dy is about 10 times brighter, 10 times longer glowing, and 10 times more expensive than ZnS:Cu. The excitation wavelengths for strontium aluminate range from 200 to 450 nm. The wavelength for its green formulation is 520 nm, its blue-green version emits at 505 nm, and the blue one emits at 490 nm. Colors with longer wavelengths can be obtained from the strontium aluminate as well, though for the price of some loss of brightness.
In these applications, the phosphor is directly added to the
plasticA plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...
used to mold the toys, or mixed with a binder for use as paints.
ZnS:Cu phosphor is used in glow-in-the-dark cosmetic creams frequently used for
HalloweenHallowe'en , also known as Halloween or All Hallows' Eve, is a yearly holiday observed around the world on October 31, the night before All Saints' Day...
make-ups.
Generally, the persistence of the phosphor increases as the wavelength increases.
See also
lightstickA glow stick is a single-use translucent plastic tube containing isolated substances which when combined make light through a chemical reaction-induced chemiluminescence which does not require an electrical power source...
for chemiluminescence-based glowing items.
Radioluminescence
Zinc sulfide phosphors are used with radioactive materials, where the phosphor was excited by the alpha- and beta-decaying isotopes, to create luminescent paint for dials of
watchA watch is a small timepiece, typically worn either on the wrist or attached on a chain and carried in a pocket, with wristwatches being the most common type of watch used today. They evolved in the 17th century from spring powered clocks, which appeared in the 15th century. The first watches were...
es and instruments (
radium dialsRadium dials are watch, clock and other instrument dials painted with radioluminescent paint containing radium. The 1900s were the peak of radium dial production, as radiation poisoning was then unknown; subsequently, radium dials have largely been replaced by tritium based light...
). Between 1913 and 1950 a radium-228 and radium-226 were used to activate a phosphor made of
silverSilver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
doped zinc sulfide (ZnS:Ag), which gave a greenish glow. The phosphor is not suitable to be used in layers thicker than 25 mg/cm², as the self-absorption of the light then becomes a problem. Furthermore, zinc sulfide undergoes degradation of its crystal lattice structure, leading to gradual loss of brightness significantly faster than the depletion of radium. ZnS:Ag coated
spinthariscopeA Spinthariscope is a device for observing individual nuclear disintegrations caused by the interaction of ionizing radiation with a phosphor or scintillator.The spinthariscope was invented by William Crookes in 1903...
screens were used by
Ernest RutherfordErnest Rutherford, 1st Baron Rutherford of Nelson OM, FRS was a New Zealand-born British chemist and physicist who became known as the father of nuclear physics...
in his experiments discovering
atomic nucleusThe nucleus is the very dense region consisting of protons and neutrons at the center of an atom. It was discovered in 1911, as a result of Ernest Rutherford's interpretation of the famous 1909 Rutherford experiment performed by Hans Geiger and Ernest Marsden, under the direction of Rutherford. The...
.
CopperCopper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
doped zinc sulfide (ZnS:Cu) is the most common phosphor used and yields blue-green light. Copper and
magnesiumMagnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
doped zinc sulfide (ZnS:Cu,Mg) yields yellow-orange light.
TritiumTritium is a radioactive isotope of hydrogen. The nucleus of tritium contains one proton and two neutrons, whereas the nucleus of protium contains one proton and no neutrons...
is also used as a source of radiation in various products utilizing tritium illumination.
Electroluminescence
ElectroluminescenceElectroluminescence is an optical phenomenon and electrical phenomenon in which a material emits light in response to the passage of an electric current or to a strong electric field...
can be exploited in light sources. Such sources typically emit from a large area, which makes them suitable for backlights of LCD displays. The excitation of the phosphor is usually achieved by application of high-intensity
electric fieldIn physics, an electric field surrounds electrically charged particles and time-varying magnetic fields. The electric field depicts the force exerted on other electrically charged objects by the electrically charged particle the field is surrounding...
, usually with suitable frequency. Current electroluminescent light sources tend to degrade with use, resulting in their relatively short operation lifetimes.
ZnS:Cu was the first formulation successfully displaying electroluminescence, tested at 1936 by Georges Destriau in Madame Marie Curie laboratories in Paris.
Indium tin oxideIndium tin oxide is a solid solution of indium oxide and tin oxide , typically 90% In2O3, 10% SnO2 by weight. It is transparent and colorless in thin layers while in bulk form it is yellowish to grey...
(
ITO, also known under trade name
IndiGlo) composite is used in some Timex watches, though as the electrode material, not as a phosphor itself. "Lighttape" is another trade name of an electroluminescent material, used in electroluminescent light strips.
White LEDs
White
light-emitting diodeA light-emitting diode is a semiconductor light source. LEDs are used as indicator lamps in many devices and are increasingly used for other lighting...
s are usually blue
InGaNIngan is a village in the Punjab province of Pakistan....
LEDs with a coating of a suitable material.
CeriumCerium is a chemical element with the symbol Ce and atomic number 58. It is a soft, silvery, ductile metal which easily oxidizes in air. Cerium was named after the dwarf planet . Cerium is the most abundant of the rare earth elements, making up about 0.0046% of the Earth's crust by weight...
(III)-doped YAG (
YAG:Ce3+, or
Y3Al5O12:Ce3+) is often used; it absorbs the light from the blue LED and emits in a broad range from greenish to reddish, with most of output in yellow. The pale yellow emission of the Ce
3+:YAG can be tuned by substituting the cerium with other rare earth elements such as
terbiumTerbium is a chemical element with the symbol Tb and atomic number 65. It is a silvery-white rare earth metal that is malleable, ductile and soft enough to be cut with a knife...
and
gadoliniumGadolinium is a chemical element with the symbol Gd and atomic number 64. It is a silvery-white, malleable and ductile rare-earth metal. It is found in nature only in combined form. Gadolinium was first detected spectroscopically in 1880 by de Marignac who separated its oxide and is credited with...
and can even be further adjusted by substituting some or all of the aluminium in the YAG with gallium. However, this process is not one of phosphorescence. The yellow light is produced by a process known as
scintillationScintillation is a flash of light produced in a transparent material by an ionization event. See scintillator and scintillation counter for practical applications.-Overview:...
, the complete absence of an afterglow being one of the characteristics of the process.
Some rare-earth doped
SialonSialon ceramics are a specialist class of high temperature refractory materials, with high strength , good thermal shock resistance and exceptional resistance to wetting or corrosion by molten non-ferrous metals, compared to other refractory materials such as, for example, alumina. A typical use...
s are photoluminescent and can serve as phosphors.
EuropiumEuropium is a chemical element with the symbol Eu and atomic number 63. It is named after the continent of Europe. It is a moderately hard silvery metal which readily oxidizes in air and water...
(II)-doped β-SiAlON absorbs in
ultravioletUltraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...
and visible light spectrum and emits intense broadband visible emission. Its luminance and color does not change significantly with temperature, due to the temperature-stable crystal structure. It has a great potential as a green down-conversion phosphor for white
LEDLEd is a TeX/LaTeX editing software working under Microsoft Windows. It is a freeware product....
s; a yellow variant also exists. For white LEDs, a blue LED is used with a yellow phosphor, or with a green and yellow SiAlON phosphor and a red CaAlSiN
3-based (CASN) phosphor.
White LEDs can also be made by coating near ultraviolet (NUV) emitting LEDs with a mixture of high efficiency europium based red and blue emitting phosphors plus green emitting copper and aluminium doped zinc sulfide (ZnS:Cu,Al). This is a method analogous to the way
fluorescent lampA fluorescent lamp or fluorescent tube is a gas-discharge lamp that uses electricity to excite mercury vapor. The excited mercury atoms produce short-wave ultraviolet light that then causes a phosphor to fluoresce, producing visible light. A fluorescent lamp converts electrical power into useful...
s work.
Cathode ray tubes
Cathode ray tubeThe cathode ray tube is a vacuum tube containing an electron gun and a fluorescent screen used to view images. It has a means to accelerate and deflect the electron beam onto the fluorescent screen to create the images. The image may represent electrical waveforms , pictures , radar targets and...
s produce signal-generated light patterns in a (typically) round or rectangular format. Bulky CRTs were used in the black-and-white household television ("TV") sets that became popular in the 1950s, as well as first-generation, tube-based color TVs, and most earlier computer monitors. CRTs have also been widely used in scientific and engineering instrumentation, such as
oscilloscopeAn oscilloscope is a type of electronic test instrument that allows observation of constantly varying signal voltages, usually as a two-dimensional graph of one or more electrical potential differences using the vertical or 'Y' axis, plotted as a function of time,...
s, usually with a single phosphor color, typically green.
White (in black-and-white): The mix of zinc cadmium sulfide and zinc sulfide silver, the ZnS:Ag+(Zn,Cd)S:Ag is the white
P4 phosphor used in black and white television CRTs.
Red: YttriumYttrium is a chemical element with symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and it has often been classified as a "rare earth element". Yttrium is almost always found combined with the lanthanides in rare earth minerals and is...
oxideAn oxide is a chemical compound that contains at least one oxygen atom in its chemical formula. Metal oxides typically contain an anion of oxygen in the oxidation state of −2....
-
sulfideA sulfide is an anion of sulfur in its lowest oxidation state of 2-. Sulfide is also a slightly archaic term for thioethers, a common type of organosulfur compound that are well known for their bad odors.- Properties :...
activated with europium is used as the red phosphor in color CRTs. The development of color TVs took a long time due to the long search for a red phosphor. The first red emitting rare earth phosphor, YVO4,Eu3, was introduced by Levine and Palilla as a primary color in television in 1964. In single crystal form, it was used as an excellent polarizer and laser material.
Yellow: When mixed with cadmium sulfide, the resulting
zinc cadmium sulfide (Zn,Cd)S:Ag, provides strong yellow light.
Green: Combination of zinc sulfide with
copperCopper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
, the
P31 phosphor or ZnS:Cu, provides green light peaking at 531 nm, with long glow.
Blue: Combination of zinc sulfide with few ppm of
silverSilver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
, the ZnS:Ag, when excited by electrons, provides strong blue glow with maximum at 450 nm, with short afterglow with 200 nanosecond duration. It is known as the
P22B phosphor. This material,
zinc sulfide silver, is still one of the most efficient phosphors in cathode ray tubes. It is used as a blue phosphor in color CRTs.
The phosphors are usually poor electrical conductors. This may lead to deposition of residual charge on the screen, effectively decreasing the energy of the impacting electrons due to electrostatic repulsion (an effect known as "sticking"). To eliminate this, a thin layer of aluminium is deposited over the phosphors and connected to the conductive layer inside the tube. This layer also reflects the phosphor light to the desired direction, and protects the phosphor from ion bombardment resulting from an imperfect vacuum.
Standard phosphor types
Standard phosphor types
| Phosphor |
CompositionA chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....
|
Color |
WavelengthIn physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...
|
Peak width |
Persistence |
Usage |
Notes |
| P1, GJ |
Zn2SiO4:Mn (WillemiteWillemite is a zinc silicate mineral and a minor ore of zinc. It is highly fluorescent under shortwave ultraviolet light.It occurs in all different colors in daylight, in fibrous masses, solid brown masses , and apple green gemmy masses.It was discovered in 1830 and named after William I of the...
) |
Green |
528 nm |
40 nm |
1-100ms |
CRT, Lamp |
Oscilloscopes and monochrome monitors |
| P2 |
? |
Blue-Green |
- |
- |
Long |
CRT |
Oscilloscopes |
| P4 |
ZnS:Ag+(Zn,Cd)S:Ag |
White |
- |
- |
Short |
CRT |
Black and white TV CRTs and display tubes. |
| P4 (Cd-free) |
ZnS:Ag+ZnS:Cu+Y2O2S:Eu |
White |
- |
- |
Short |
CRT |
Black and white TV CRTs and display tubes, Cd free. |
| P4, GE |
ZnOZinc oxide is an inorganic compound with the formula ZnO. It is a white powder that is insoluble in water. The powder is widely used as an additive into numerous materials and products including plastics, ceramics, glass, cement, rubber , lubricants, paints, ointments, adhesives, sealants,...
:Zn |
Green |
505 nm |
- |
1-10µs |
VFD |
VFDA vacuum fluorescent display is a display device used commonly on consumer-electronics equipment such as video cassette recorders, car radios, and microwave ovens. Invented in Japan in 1967, the displays became common on calculators and other consumer electronics devices...
s |
| P5 |
|
Blue |
- |
- |
Very Short |
CRT |
Film |
| P7 |
|
Blue with Yellow persistence |
- |
- |
Long |
CRT |
RadarRadar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
PPIThe plan position indicator , is the most common type of radar display. The radar antenna is usually represented in the center of the display, so the distance from it and height above ground can be drawn as concentric circles...
, old EKG monitors |
| P10 |
KCl |
green-absorbing scotophor A scotophor is a material showing reversible darkening and bleaching when subjected to certain types of radiation. The name means dark bearer, in contrast to phosphor, which means light bearer. Scotophors show tenebrescence and darken when subjected to an intense radiation such as sunlight...
|
- |
- |
Long |
Dark-trace CRTs |
Radar screens; turns from translucent white to dark magenta, stays changed until erased by heating or infrared light |
| P11, BE |
ZnS:Ag,Cl or ZnS:Zn |
Blue |
460 nm |
- |
0.01-1 ms |
CRT, VFD |
Display tubes and VFDA vacuum fluorescent display is a display device used commonly on consumer-electronics equipment such as video cassette recorders, car radios, and microwave ovens. Invented in Japan in 1967, the displays became common on calculators and other consumer electronics devices...
s |
| P12 |
- |
Orange |
- |
- |
Medium/Long |
CRT |
RadarRadar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
|
| P14 |
|
Blue with Orange persistence |
- |
- |
Medium/Long |
CRT |
RadarRadar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
PPIThe plan position indicator , is the most common type of radar display. The radar antenna is usually represented in the center of the display, so the distance from it and height above ground can be drawn as concentric circles...
, old EKG monitors |
| P15 |
|
Blue-Green |
- |
- |
Extremely Short |
CRT |
|
| P19, LF |
(KF,MgF2):Mn |
Orange-Yellow |
590 nm |
- |
Long |
CRT |
Radar screens |
| P20, KA |
(Zn,Cd)S:Ag or (Zn,Cd)S:Cu |
Yellow-green |
- |
- |
1-100 ms |
CRT |
Display tubes |
| P22R |
Y2O2S:Eu+Fe2O3 |
Red |
- |
- |
Short |
CRT |
Red phosphor for TV screens |
| P22G |
ZnS:Cu,Al |
Green |
- |
- |
Short |
CRT |
Green phosphor for TV screens |
| P22B |
ZnS:Ag+Co Cobalt is a chemical element with symbol Co and atomic number 27. It is found naturally only in chemically combined form. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal....
-on-Al2O3Aluminium oxide is an amphoteric oxide with the chemical formula 23. It is commonly referred to as alumina, or corundum in its crystalline form, as well as many other names, reflecting its widespread occurrence in nature and industry...
|
Blue |
- |
- |
Short |
CRT |
Blue phosphor for TVTelevision is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...
screens |
| P26, LC |
(KF,MgF2):Mn |
Orange |
595 nm |
- |
Long |
CRT |
Radar screens |
| P28, KE |
(Zn,Cd)S:Cu,Cl |
Yellow |
- |
- |
- |
CRT |
Display tubes |
| P31, GH |
ZnS:Cu or ZnS:Cu,Ag |
Yellowish-green |
- |
- |
0.01-1 ms |
CRT |
Oscilloscopes |
| P33, LD |
MgF2:Mn |
Orange |
590 nm |
- |
> 1sec |
CRT |
Radar screens |
| P38, LK |
(Zn,Mg)F2:Mn |
Orange-Yellow |
590 nm |
- |
Long |
CRT |
Radar screens |
| P39, GR |
Zn2SiO4:Mn,As |
Green |
525 nm |
- |
- |
CRT |
Display tubes |
| P40, GA |
ZnS:Ag+(Zn,Cd)S:Cu |
White |
- |
- |
- |
CRT |
Display tubes |
| P43, GY |
Gd2O2S Gadolinium oxysulfide , also called gadolinium sulfoxylate or GOS, is an inorganic compound, a mixed oxide-sulfide of gadolinium. Its CAS number is .-Uses:...
:Tb |
Yellow-green |
545 nm |
- |
- |
CRT |
Display tubes |
| P45, WB |
Y2O2S:Tb |
White |
545 nm |
- |
Short |
CRT |
Viewfinders |
| P46, KG |
Y3Al5O12:Ce |
Green |
530 nm |
- |
- |
CRT |
Beam-index tube The beam-index tube is a color television cathode ray tube design, using phosphor stripes and active-feedback timing, rather than phosphor dots and a beam-shadowing mask as developed by RCA...
|
| P47, BH |
Y2SiO5:Ce |
Blue |
400 nm |
- |
- |
CRT |
Beam-index tube |
| P53, KJ |
Y3Al5O12:Tb |
Yellow-green |
544 nm |
- |
Short |
CRT |
Projection tubes |
| P55, BM |
ZnS:Ag,Al |
Blue |
450 nm |
- |
Short |
CRT |
Projection tubes |
|
ZnS:Ag |
Blue |
450 nm |
- |
- |
CRT |
- |
|
ZnS:Cu,Al or ZnS:Cu,Au,Al |
Green |
530 nm |
- |
- |
CRT |
- |
|
(Zn,Cd)S:Cu,Cl+(Zn,Cd)S:Ag,Cl |
White |
- |
- |
- |
CRT |
- |
|
Y2SiO5:Tb |
Green |
545 nm |
- |
- |
CRT |
Projection tubes |
|
Y2OS:Tb |
Green |
545 nm |
- |
- |
CRT |
Display tubes |
|
Y3(Al,Ga)5O12:Ce |
Green |
520 nm |
- |
Short |
CRT |
Beam-index tube |
|
Y3(Al,Ga)5O12:Tb |
Yellow-green |
544 nm |
- |
Short |
CRT |
Projection tubes |
|
InBO3:Tb |
Yellow-green |
550 nm |
- |
- |
CRT |
- |
|
InBO3:Eu |
Yellow |
588 nm |
- |
- |
CRT |
- |
|
InBO3:Tb+InBO3:Eu |
amber |
- |
- |
- |
CRT |
Computer displays |
|
InBO3:Tb+InBO3:Eu+ZnS:Ag |
White |
- |
- |
- |
CRT |
- |
|
(Ba,Eu)Mg2Al16O27 |
Blue |
- |
- |
- |
Lamp |
Trichromatic fluorescent lamps |
|
(Ce,Tb)MgAl11O19 |
Green |
546 nm |
9 nm |
- |
Lamp |
Trichromatic fluorescent lamps |
| BAM |
BaMgAl10O17:Eu,Mn |
Blue |
450 nm |
- |
- |
Lamp, displays |
Trichromatic fluorescent lamps |
|
BaMg2Al16O27:Eu(II) |
Blue |
450 nm |
52 nm |
- |
Lamp |
Trichromatic fluorescent lamps |
| BAM |
BaMgAl10O17:Eu,Mn |
Blue-Green |
456 nm,514 nm |
- |
- |
Lamp |
- |
|
BaMg2Al16O27:Eu(II),Mn(II) |
Blue-Green |
456 nm, 514 nm |
50 nm 50% |
- |
Lamp |
|
|
Ce0.67Tb0.33MgAl11O19:Ce,Tb |
Green |
543 nm |
- |
- |
Lamp |
Trichromatic fluorescent lamps |
|
Zn2SiO4:Mn,Sb2O3 |
Green |
528 nm |
- |
- |
Lamp |
- |
|
CaSiO3Calcium silicate is the chemical compound Ca2SiO4, also known as calcium orthosilicate and sometimes formulated 2CaO.SiO2. It is one of group of compounds obtained by reacting calcium oxide and silica in various ratios e.g. 3CaO.SiO2, Ca3SiO5; 2CaO.SiO2, Ca2SiO4; 3CaO.2SiO2, Ca3Si2O7 and...
:Pb,Mn |
Orange-Pink |
615 nm |
83 nm |
- |
Lamp |
|
|
CaWO4 (Scheelite Scheelite is a calcium tungstate mineral with the chemical formula CaWO4. It is an important ore of tungsten. Well-formed crystals are sought by collectors and are occasionally fashioned into gemstones when suitably free of flaws...
) |
Blue |
417 nm |
- |
- |
Lamp |
- |
|
CaWO4:Pb |
Blue |
433 nm/466 nm |
111 nm |
- |
Lamp |
Wide bandwidth |
|
MgWO4 |
Blue pale |
473 nm |
118 nm |
- |
Lamp |
Wide bandwidth, deluxe blend component |
|
(Sr,Eu,Ba,Ca)5(PO4)3Cl |
Blue |
- |
- |
- |
Lamp |
Trichromatic fluorescent lamps |
|
Sr5Cl(PO4)3:Eu(II) |
Blue |
447 nm |
32 nm |
- |
Lamp |
- |
|
(Ca,Sr,Ba)3(PO4)2Cl2:Eu |
Blue |
452 nm |
- |
- |
Lamp |
- |
|
(Sr,Ca,Ba)10(PO4)6Cl2:Eu |
Blue |
453 nm |
- |
- |
Lamp |
Trichromatic fluorescent lamps |
|
Sr2P2O7:Sn(II) |
Blue |
460 nm |
98 nm |
- |
Lamp |
Wide bandwidth, deluxe blend component |
|
Sr6P5BO20:Eu |
Blue-Green |
480 nm |
82 nm |
- |
Lamp |
- |
|
Ca5F(PO4)3:Sb |
Blue |
482 nm |
117 nm |
- |
Lamp |
Wide bandwidth |
|
(Ba,Ti)2P2O7:Ti |
Blue-Green |
494 nm |
143 nm |
- |
Lamp |
Wide bandwidth, deluxe blend component |
|
3Sr3(PO4)2.SrF2 Strontium fluoride, SrF2, also called strontium difluoride and strontium fluoride, is a fluoride of strontium. It is a stable brittle white crystalline solid with melting point of 1477°C and boiling point 2460°C.-Preparation:...
:Sb,Mn |
Blue |
502 nm |
- |
- |
Lamp |
- |
|
Sr5F(PO4)3:Sb,Mn |
Blue-Green |
509 nm |
127 nm |
- |
Lamp |
Wide bandwidth |
|
Sr5F(PO4)3:Sb,Mn |
Blue-Green |
509 nm |
127 nm |
- |
Lamp |
Wide bandwidth |
|
LaPO4:Ce,Tb |
Green |
544 nm |
- |
- |
Lamp |
Trichromatic fluorescent lamps |
|
(La,Ce,Tb)PO4 |
Green |
- |
- |
- |
Lamp |
Trichromatic fluorescent lamps |
|
(La,Ce,Tb)PO4:Ce,Tb |
Green |
546 nm |
6 nm |
- |
Lamp |
Trichromatic fluorescent lamps |
|
Ca3(PO4)2Calcium phosphate is the name given to a family of minerals containing calcium ions together with orthophosphates , metaphosphates or pyrophosphates and occasionally hydrogen or hydroxide ions ....
.CaF2Calcium fluoride is the inorganic compound with the formula CaF2. This ionic compound of calcium and fluorine occurs naturally as the mineral fluorite . It is the source of most of the world's fluorine. This insoluble solid adopts a cubic structure wherein calcium is coordinated to eight fluoride...
:Ce,Mn |
Yellow |
568 nm |
- |
- |
Lamp |
- |
|
(Ca,Zn,Mg)3(PO4)2:Sn |
Orange-Pink |
610 nm |
146 nm |
- |
Lamp |
Wide bandwidth, blend component |
|
(Zn,Sr)3(PO4)2:Mn |
Orange-Red |
625 nm |
- |
- |
Lamp |
- |
|
(Sr,Mg)3(PO4)2:Sn |
Orange-Pinkish White |
626 nm |
120 nm |
- |
Fluorescent Lamps |
Wide bandwidth, deluxe blend component |
|
(Sr,Mg)3(PO4)2:Sn(II) |
Orange-Red |
630 nm |
- |
- |
Fluorescent Lamps |
- |
|
Ca5F(PO4)3:Sb,Mn |
3800K |
- |
- |
- |
Fluorescent Lamps |
Lite-white blend |
|
Ca5(F,Cl)(PO4)3:Sb,Mn |
White-Cold/Warm |
- |
- |
- |
Fluorescent Lamps |
2600K to 9900K, for very high output lamps |
|
(Y,Eu)2O3 |
Red |
- |
- |
- |
Lamp |
Trichromatic fluorescent lamps |
|
Y2O3:Eu(III) |
Red |
611 nm |
4 nm |
- |
Lamp |
Trichromatic fluorescent lamps |
|
Mg4(F)GeO6:Mn |
Red |
658 nm |
17 nm |
- |
High Pressure Mercury Lamps |
|
|
Mg4(F)(Ge,Sn)O6:Mn |
Red |
658 nm |
- |
- |
Lamp |
- |
|
Y(P,V)O4:Eu |
Orange-Red |
619 nm |
- |
- |
Lamp |
- |
|
YVO4:Eu |
Orange-Red |
619 nm |
- |
- |
High Pressure Mercury and Metal Halide Lamps |
- |
|
Y2O2S:Eu |
Red |
626 nm |
- |
- |
Lamp |
- |
|
3.5 MgO Magnesium oxide , or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium . It has an empirical formula of and consists of a lattice of Mg2+ ions and O2– ions held together by ionic bonds...
· 0.5 MgF2 · GeO2 :Mn |
Red |
655 nm |
- |
- |
Lamp |
3.5 MgO Magnesium oxide , or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium . It has an empirical formula of and consists of a lattice of Mg2+ ions and O2– ions held together by ionic bonds...
· 0.5 MgF2Magnesium fluoride is an inorganic compound with the formula MgF2. The compound is a white crystalline salt and is transparent over a wide range of wavelengths, with commercial uses in optics.-Production and structure:...
· GeO2Germanium dioxide, also called germanium oxide and germania, is an inorganic compound, an oxide of germanium. Its chemical formula is GeO2. Other names include germanic acid, G-15, and ACC10380...
:Mn |
|
Mg5As2O11:Mn |
Red |
660 nm |
- |
- |
High Pressure Mercury Lamps, 1960s |
- |
|
SrAl2O7:Pb |
Ultraviolet |
313 nm |
- |
- |
Special Fluorescent Lamps for Medical use |
Ultraviolet |
| CAM |
LaMgAl11O19:Ce |
Ultraviolet |
340 nm |
52 nm |
- |
Black-light Fluorescent Lamps |
Ultraviolet |
| LAP |
LaPO4:Ce |
Ultraviolet |
320 nm |
38 nm |
- |
Medical and scientific U.V. Lamps |
Ultraviolet |
| SAC |
SrAl12O19:Ce |
Ultraviolet |
295 nm |
34 nm |
- |
Lamp |
Ultraviolet |
| BSP |
BaSi2O5:Pb |
Ultraviolet |
350 nm |
40 nm |
- |
Lamp |
Ultraviolet |
|
SrFB2O3:Eu(II) |
Ultraviolet |
366 nm |
- |
- |
Lamp |
Ultraviolet |
| SBE |
SrB4O7:Eu |
Ultraviolet |
368 nm |
15 nm |
- |
Lamp |
Ultraviolet |
| SMS |
Sr2MgSi2O7:Pb |
Ultraviolet |
365 nm |
68 nm |
- |
Lamp |
Ultraviolet |
|
MgGa2O4:Mn(II) |
Blue-Green |
- |
- |
- |
Lamp |
Black light displays |
Various
Some other phosphors commercially available, for use as
X-rayX-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
screens, neutron detectors,
alpha particleAlpha particles consist of two protons and two neutrons bound together into a particle identical to a helium nucleus, which is classically produced in the process of alpha decay, but may be produced also in other ways and given the same name...
scintillatorA scintillator is a special material, which exhibits scintillation—the property of luminescence when excited by ionizing radiation. Luminescent materials, when struck by an incoming particle, absorb its energy and scintillate, i.e., reemit the absorbed energy in the form of light...
s, etc., are:
- Gd2O2S:Tb (P43), green (peak at 545 nm), 1.5 ms decay to 10%, low afterglow, high X-ray absorption, for X-ray, neutrons and gamma
- Gd2O2S:Eu, red (627 nm), 850 µs decay, afterglow, high X-ray absorption, for X-ray, neutrons and gamma
- Gd2O2S:Pr, green (513 nm), 7 µs decay, no afterglow, high X-ray absorption, for X-ray, neutrons and gamma
- Gd2O2S:Pr,Ce,F, green (513 nm), 4 µs decay, no afterglow, high X-ray absorption, for X-ray, neutrons and gamma
- Y2O2S:Tb (P45), white (545 nm), 1.5 ms decay, low afterglow, for low-energy X-ray
- Y2O2S:Eu (P22R), red (627 nm), 850 µs decay, afterglow, for low-energy X-ray
- Y2O2S:Pr, white (513 nm), 7 µs decay, no afterglow, for low-energy X-ray
- Zn(0.5)Cd(0.4)S:Ag (HS), green (560 nm), 80 µs decay, afterglow, efficient but low-res X-ray
- Zn(0.4)Cd(0.6)S:Ag (HSr), red (630 nm), 80 µs decay, afterglow, efficient but low-res X-ray
- CdWO4, blue (475 nm), 28 µs decay, no afterglow, intensifying phosphor for X-ray and gamma
- CaWO4, blue (410 nm), 20 µs decay, no afterglow, intensifying phosphor for X-ray
- MgWO4, white (500 nm), 80 µs decay, no afterglow, intensifying phosphor
- Y2SiO5:Ce (P47), blue (400 nm), 120 ns decay, no afterglow, for electrons, suitable for photomultipliers
- YAlO3:Ce (YAP), blue (370 nm), 25 ns decay, no afterglow, for electrons, suitable for photomultipliers
- Y3Al5O12:Ce (YAG), green (550 nm), 70 ns decay, no afterglow, for electrons, suitable for photomultipliers
- Y3(Al,Ga)5O12:Ce (YGG), green (530 nm), 250 ns decay, low afterglow, for electrons, suitable for photomultipliers
- CdS:In, green (525 nm), <1 ns decay, no afterglow, ultrafast, for electrons
- ZnO:Ga, blue (390 nm), <5 ns decay, no afterglow, ultrafast, for electrons
- ZnO:Zn (P15), blue (495 nm), 8 µs decay, no afterglow, for low-energy electrons
- (Zn,Cd)S:Cu,Al (P22G), green (565 nm), 35 µs decay, low afterglow, for electrons
- ZnS:Cu,Al,Au (P22G), green (540 nm), 35 µs decay, low afterglow, for electrons
- ZnCdS:Ag,Cu (P20), green (530 nm), 80 µs decay, low afterglow, for electrons
- ZnS:Ag (P11), blue (455 nm), 80 µs decay, low afterglow, for alpha particles and electrons
- anthracene
Anthracene is a solid polycyclic aromatic hydrocarbon consisting of three fused benzene rings. It is a component of coal-tar. Anthracene is used in the production of the red dye alizarin and other dyes...
, blue (447 nm), 32 ns decay, no afterglow, for alpha particles and electrons
- plastic (EJ-212), blue (400 nm), 2.4 ns decay, no afterglow, for alpha particles and electrons
- Zn2SiO4:Mn (P1), green (530 nm), 11 ms decay, low afterglow, for electrons
- ZnS:Cu (GS), green (520 nm), decay in minutes, long afterglow, for X-rays
- NaI
Sodium iodide is a white, crystalline salt with chemical formula NaI used in radiation detection, treatment of iodine deficiency, and as a reactant in the Finkelstein reaction.-Uses:Sodium iodide is commonly used to treat and prevent iodine deficiency....
:Tl, for X-ray, alpha, and electrons
- CsI
Caesium iodide is an ionic compound often used as the input phosphor of an x-ray image intensifier tube found in fluoroscopy equipment....
:Tl, green (545 nm), 5 µs decay, afterglow, for X-ray, alpha, and electrons
- 6LiF
Lithium fluoride is an inorganic compound with the formula LiF. It is the lithium salt of hydrofluoric acid. This white solid is a simple ionic compound. Its structure is analogous to that of sodium chloride, but it is much less soluble in water. It is mainly used as a component of molten...
/ZnS:Ag (ND), blue (455 nm), 80 µs decay, for thermal neutrons
- 6LiF/ZnS:Cu,Al,Au (NDg), green (565 nm), 35 µs decay, for neutron
The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of...
s
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