Home      Discussion      Topics      Dictionary      Almanac
Signup       Login
Phosphor

Phosphor

Overview

Discussion
Ask a question about 'Phosphor'
Start a new discussion about 'Phosphor'
Answer questions from other users
Full Discussion Forum
 
Unanswered Questions
Encyclopedia



A phosphor, most generally, is a substance that exhibits the phenomenon
Optical phenomenon
An 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 luminescence
Luminescence
Luminescence 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 phosphorescent
Phosphorescence
Phosphorescence 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 fluorescent
Fluorescence
Fluorescence 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 metal
Transition metal
The 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 earth
Rare earth element
As 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 CRT
Cathode ray tube
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...

 displays and fluorescent lights. CRT phosphors were standardized beginning around World War II
World War II
World 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.

Phosphorus
Phosphorus
Phosphorus 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 incandescence
Incandescence
Incandescence 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 luminescence
Luminescence
Luminescence 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 dopant
Dopant
A 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 activators
Activator (phosphor)
In 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 dislocation
Dislocation
In 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 structure
Electronic band structure
In 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 crystal
Crystal
A 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 band
Valence band
In 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 band
Conduction band
In 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 exciton
Exciton
An 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 hole
Electron hole
An 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 scintillator
Scintillator
A 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 photomultiplier
Photomultiplier
Photomultiplier 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 mechanism
Forbidden mechanism
In 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 valence
Valence (chemistry)
In 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
    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, diffusion
    Diffusion
    Molecular 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 transfer
    Electron transfer
    Electron 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 phosphate
    Aluminium phosphate
    Aluminium 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 hydrogen
    Hydrogen
    Hydrogen 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 agent
    Reducing agent
    A 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 argon
    Argon
    Argon 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
    Carrier generation and recombination
    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
    Cathode ray tube
    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 FED
    Field emission display
    A 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 species
    Reactive oxygen species
    Reactive 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 monoxide
    Carbon monoxide
    Carbon 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 dioxide
    Carbon dioxide
    Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

     with traces of carbon
    Carbon
    Carbon 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 oxide
    Zinc oxide
    Zinc 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 sulfate
    Zinc sulfate
    Zinc 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 hydrogen
    Hydrogen
    Hydrogen 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 sulfur
    Sulfur
    Sulfur 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 sulfide
    Hydrogen sulfide
    Hydrogen 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 zinc
    Zinc
    Zinc , 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 oxide
    Sulfur oxide
    Sulfur 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 activator
Activator (phosphor)
In 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 oxide
Oxide
An 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, nitride
Nitride
In 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, sulfide
Sulfide
A 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, selenide
Selenide
A 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, halide
Halide
A 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 silicate
Silicate
A 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 zinc
Zinc
Zinc , 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...

, cadmium
Cadmium
Cadmium 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...

, manganese
Manganese
Manganese 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...

, aluminium
Aluminium
Aluminium 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....

, silicon
Silicon
Silicon 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 earth
Rare earth element
As 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 nickel
Nickel
Nickel 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 lamp
Fluorescent lamp
A 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 contamination
Contamination
Contamination 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 beryllium
Beryllium
Beryllium 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...

, cadmium
Cadmium
Cadmium 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 thallium
Thallium
Thallium 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 wavelength
Wavelength
In 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 temperature
Color temperature
Color 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 lamp
Fluorescent lamp
A 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 lamp
Metal halide lamp
Metal-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 sign
Neon sign
Neon 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 display
Electroluminescent display
Electroluminescent 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 thermometry
Phosphor thermometry
Phosphor 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
    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 sulfide
    Strontium sulfide
    Strontium 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 bismuth
    Bismuth
    Bismuth 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
    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 copper
    Copper
    Copper 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
    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
    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 europium
    Europium
    Europium 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 plastic
Plastic
A 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 Halloween
Halloween
Hallowe'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 lightstick
Lightstick
A 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 watch
Watch
A 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 dials
Radium dials
Radium 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 silver
Silver
Silver 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 spinthariscope
Spinthariscope
A 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 Rutherford
Ernest Rutherford
Ernest 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 nucleus
Atomic nucleus
The 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...

.

Copper
Copper
Copper 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 magnesium
Magnesium
Magnesium 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.

Tritium
Tritium
Tritium 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



Electroluminescence
Electroluminescence
Electroluminescence 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 field
Electric field
In 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 oxide
Indium tin oxide
Indium 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 diode
Light-emitting diode
A 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 InGaN
Ingan
Ingan is a village in the Punjab province of Pakistan....

 LEDs with a coating of a suitable material. Cerium
Cerium
Cerium 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 Ce3+:YAG can be tuned by substituting the cerium with other rare earth elements such as terbium
Terbium
Terbium 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 gadolinium
Gadolinium
Gadolinium 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 scintillation
Scintillation (physics)
Scintillation 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 Sialon
Sialon
Sialon 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. Europium
Europium
Europium 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 ultraviolet
Ultraviolet
Ultraviolet 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 LED
LEd
LEd 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 CaAlSiN3-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 lamp
Fluorescent lamp
A 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 tube
Cathode ray tube
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 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 oscilloscope
Oscilloscope
An 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: Yttrium
Yttrium
Yttrium 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...

 oxide
Oxide
An 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....

-sulfide
Sulfide
A 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 copper
Copper
Copper 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 silver
Silver
Silver 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 Composition
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....

Color Wavelength
Wavelength
In 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 (Willemite
Willemite
Willemite 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 ZnO
Zinc oxide
Zinc 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 VFD
Vacuum fluorescent display
A 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 Radar
Radar
Radar 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...

 PPI
Plan position indicator
The 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
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 VFD
Vacuum fluorescent display
A 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 Radar
Radar
Radar 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 Radar
Radar
Radar 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...

 PPI
Plan position indicator
The 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
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-Al2O3
Aluminium oxide
Aluminium 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 TV
Television
Television 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
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
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 -
CaSiO3
Calcium silicate
Calcium 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
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
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)2
Calcium phosphate
Calcium 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 ....

.CaF2
Calcium fluoride
Calcium 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
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
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
Magnesium fluoride
Magnesium 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:...

 · GeO2
Germanium dioxide
Germanium 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-ray
X-ray
X-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 particle
Alpha particle
Alpha 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...

 scintillator
Scintillator
A 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
    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
    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
    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
    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
    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

External links