Editing Phosphor (section)

==Applications==

===Lighting===
Phosphor layers provide most of the light produced by [[fluorescent lamp]]s, and are also used to improve the balance of light produced by [[metal halide lamp]]s.  Various [[neon sign]]s use phosphor layers to produce different colors of light. [[Electroluminescent display]]s found, for example, in aircraft instrument panels, use a phosphor layer to produce glare-free illumination or as numeric and graphic display devices. Most white [[LED]] lamps consist of a blue or ultra-violet emitter with a phosphor coating that emits at longer wavelengths, giving a full spectrum of visible light. Unfocused and undeflected [[cathode-ray tube]]s have been used as [[Strobe light|stroboscope lamps]] since 1958.<ref>{{cite web |url=http://www.mif.pg.gda.pl/homepages/frank/sheets/074/c/CL60.pdf |publisher=[[Ferranti]], Ltd. |title=''Vacuum light sources — High speed stroboscopic light sources'' data sheet |date=August 1958 |access-date=7 May 2017 |url-status=live |archive-url=https://web.archive.org/web/20160920125303/http://www.mif.pg.gda.pl/homepages/frank/sheets/074/c/CL60.pdf |archive-date=20 September 2016 }}</ref>

===Phosphor thermometry===
{{main|Phosphor thermometry}}
[[Phosphor thermometry]] is a temperature measurement approach that uses the temperature dependence of certain phosphors. 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.{{Citation needed|date=December 2023}}

===Glow-in-the-dark toys===
{{main|Phosphorescence}}
In these applications, the phosphor is directly added to the [[plastic]] 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]] [[make-up]]s.
Generally, the persistence of the phosphor increases as the wavelength increases. 
See also [[lightstick]] for [[chemiluminescence]]-based glowing items.

===Oxygen sensing===
Quenching of the triplet state by O<sub>2</sub> (which has a triplet ground state) as a result of [[Dexter electron transfer|Dexter energy transfer]] is well known in solutions of phosphorescent heavy-metal complexes and doped polymers.<ref>{{Cite journal|last1=Lehner|first1=P.|last2=Staudinger|first2=C.|last3=Borisov|first3=S. M.|last4=Klimant|first4=l.|title=Ultra-sensitive optical oxygen sensors for characterization of nearly anoxic systems|journal= Nature Communications|date=2014|volume=5|page=4460|doi=10.1038/ncomms5460 |pmid=25042041 |pmc=4109599 |bibcode=2014NatCo...5.4460L }}</ref> In recent years, phosphorescence porous materials(such as [[Metal–organic framework]]s and [[Covalent organic framework]]s) have shown promising oxygen sensing capabilities, for their non-linear gas-adsorption in ultra-low partial pressures of oxygen.<ref>{{Cite journal|last1=Hamzehpoor|first1=E|last2=Ruchlin|first2=C.|last3=Tao|first3=Y.|last4=Liu|first4=C. H.|last5=Titi|first5=H. M.|last6=Perepichka|first6=D. F.|title=Efficient room-temperature phosphorescence of covalent organic frameworks through covalent halogen doping|journal=Nature Chemistry|date=2022|volume=15|issue=1|pages=83–90|doi=10.1038/s41557-022-01070-4|pmid=36302870|s2cid=253183290}}</ref><ref>{{Cite journal|last1=Xie|first1=Z.|last2=Ma|first2=L.|last3=deKrafft|first3=K. E.|last4=Jin|first4=A.|last5=Lin|first5=W.|title=Porous phosphorescent coordination polymers for oxygen sensing|journal=J. Am. Chem. Soc.|date=2010|volume=132|issue=3 |pages=922–923|doi=10.1021/ja909629f |pmid=20041656 |bibcode=2010JAChS.132..922X }}</ref>

===Postage stamps===
[[Phosphor banded stamp]]s first appeared in 1959 as guides for machines to sort mail.<ref>[http://www.stamp-shop.com/dummies/see-phosphor.html SEEING PHOSPHOR BANDS on U.K. STAMPS] {{webarchive|url=https://web.archive.org/web/20151019005044/http://www.stamp-shop.com/dummies/see-phosphor.html |date=2015-10-19 }}.</ref>  Around the world many varieties exist with different amounts of banding.<ref>[http://www.gbmachins.co.uk/html/phosphor_bands.html Phosphor Bands] {{webarchive|url=https://web.archive.org/web/20170317231538/http://gbmachins.co.uk/html/phosphor_bands.html |date=2017-03-17 }}.</ref>  [[Postage stamp]]s are sometimes collected by whether or not they are [[Tagging (stamp)|"tagged"]] with phosphor (or printed on [[luminescent]] paper).

===Radioluminescence===
{{main|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]]es and instruments ([[radium dials]]). Between 1913 and 1950 radium-228 and radium-226 were used to activate a phosphor made of [[silver]] [[dopant|doped]] zinc sulfide (ZnS:Ag), which gave a greenish glow. The phosphor is not suitable to be used in layers thicker than 25&nbsp;mg/cm<sup>2</sup>, 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]] screens were used by [[Ernest Rutherford]] in his experiments discovering [[atomic nucleus]].

[[Copper]] doped zinc sulfide (ZnS:Cu) is the most common phosphor used and yields blue-green light. Copper and [[magnesium]] doped zinc sulfide {{chem2|(ZnS:Cu,Mg)}} yields yellow-orange light.

[[Tritium]] is also used as a source of radiation in various products utilizing [[tritium illumination]].

===Electroluminescence===
{{main|Electroluminescence}}
[[Electroluminescence]] 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]], 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.

Powder or AC electroluminescence is found in a variety of backlight and night light applications.  Several groups offer branded EL offerings (e.g. '''IndiGlo''' used in some Timex watches) or "Lighttape", another trade name of an electroluminescent material, used in electroluminescent [[light strips]].  The Apollo space program is often credited with being the first significant use of EL for backlights and lighting.<ref>{{cite web |url=https://www.hq.nasa.gov/alsj/tnD7290Lighting.pdf |title=Apollo Lunar Surface Journal |access-date=2017-02-12 |url-status=live |archive-url=https://web.archive.org/web/20161221230335/http://www.hq.nasa.gov/alsj/tnD7290Lighting.pdf |archive-date=2016-12-21 }}</ref>

===White LEDs===
White [[light-emitting diode]]s are usually blue [[InGaN]] LEDs with a coating of a suitable material. [[Cerium]](III)-doped [[Yttrium aluminium garnet|YAG]] ('''YAG:Ce<sup>3+</sup>''', or '''Y<sub>3</sub>Al<sub>5</sub>O<sub>12</sub>:Ce<sup>3+</sup>''') is often used; it absorbs the light from the blue LED and emits in a broad range from greenish to reddish, with most of its output in yellow. This yellow emission combined with the remaining blue emission gives the "white" light, which can be adjusted to color temperature as warm (yellowish) or cold (bluish) white. The pale yellow emission of the Ce<sup>3+</sup>:YAG can be tuned by substituting the cerium with other rare-earth elements such as [[terbium]] and [[gadolinium]] 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 (physics)|scintillation]], the complete absence of an afterglow being one of the characteristics of the process.

Some [[rare-earth]]-[[dopant|doped]] [[Sialon]]s are [[photoluminescent]] and can serve as phosphors. [[Europium]](II)-doped β-SiAlON absorbs in [[ultraviolet]] 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]]s; a yellow variant also exists (α-SiAlON<ref>{{Cite web|url=https://tech.nikkeibp.co.jp/dm/english/NEWS_EN/20090915/175305/|title=Sharp to Employ White LED Using Sialon|last=XTECH|first=NIKKEI|website=NIKKEI XTECH|language=en|access-date=2019-01-10}}</ref>). For white LEDs, a blue LED is used with a yellow phosphor, or with a green and yellow SiAlON phosphor and a red CaAlSiN<sub>3</sub>-based (CASN) phosphor.<ref>{{cite journal|url=http://www.science24.com/paper/15977|title=Luminescence and temperature dependency of β-SiAlON phosphor|author=Youn-Gon Park|journal=Samsung Electro Mechanics Co|display-authors=etal|url-status=dead|archive-url=https://web.archive.org/web/20100412152349/http://www.science24.com/paper/15977|archive-date=2010-04-12|access-date=2009-09-24}}</ref><ref>{{cite news|url=http://techon.nikkeibp.co.jp/english/NEWS_EN/20090915/175305/|title=Sharp to Employ White LED Using Sialon|date=Sep 15, 2009|author=Hideyoshi Kume, Nikkei Electronics|url-status=live|archive-url=https://web.archive.org/web/20120223124648/http://techon.nikkeibp.co.jp/english/NEWS_EN/20090915/175305/|archive-date=2012-02-23}}</ref><ref>{{cite journal|url=http://sciencelinks.jp/j-east/article/200602/000020060205A1031052.php|title=New sialon phosphors and white LEDs|author=Naoto, Hirosaki|journal=Oyo Butsuri|volume=74|issue=11|page=1449|year=2005|display-authors=etal|url-status=dead|archive-url=https://web.archive.org/web/20100404151444/http://sciencelinks.jp/j-east/article/200602/000020060205A1031052.php|archive-date=2010-04-04}}</ref>

White LEDs can also be made by coating near-ultraviolet-emitting LEDs with a mixture of high-efficiency europium-based red- and blue-emitting phosphors plus green-emitting copper- and aluminium-doped zinc sulfide {{chem2|(ZnS:Cu,Al)}}. This is a method analogous to the way [[fluorescent lamp]]s work.

Some newer white LEDs use a yellow and blue emitter in series, to approximate white; this technology is used in some Motorola phones such as the Blackberry as well as LED lighting and the original-version stacked emitters by using GaN on SiC on InGaP but was later found to fracture at higher drive currents.

Many white LEDs used in general lighting systems can be used for data transfer, as, for example, in systems that modulate the LED to act as a [[beacon]].<ref>{{cite journal|url=http://ntv.ifmo.ru/en/article/11192/chastotnye_harakteristiki_sovremennyh_svetodiodnyh_lyuminofornyh_materialov.htm|title=Frequency characteristics of modern LED phosphor materials|author=Fudin, M.S.|journal=Scientific and Technical Journal of Information Technologies, Mechanics and Optics|volume=14|issue=6|page=71|year=2014|display-authors=etal|url-status=live|archive-url=https://web.archive.org/web/20150626162616/http://ntv.ifmo.ru/en/article/11192/chastotnye_harakteristiki_sovremennyh_svetodiodnyh_lyuminofornyh_materialov.htm|archive-date=2015-06-26}}</ref>

It is also common for white LEDs to use phosphors other than Ce:YAG, or to use two or three phosphors to achieve a higher CRI, often at the cost of efficiency. Examples of additional phosphors are R9, which produces a saturated red, nitrides which produce red, and aluminates such as lutetium aluminum garnet that produce green. Silicate phosphors are brighter but fade more quickly, and are used in LCD LED backlights in mobile devices. LED phosphors can be placed directly over the die or made into a dome and placed above the LED: this approach is known as a remote phosphor.<ref>{{Cite web|url=https://www.electronicsweekly.com/news/products/led/discussing-led-lighting-phosphors-2014-03/|title=Discussing LED lighting phosphors|first=Steve|last=Bush|date=March 14, 2014}}</ref> Some colored LEDs, instead of using a colored LED, use a blue LED with a colored phosphor because such an arrangement is more efficient than a colored LED. Oxynitride phosphors can also be used in LEDs. The precursors used to make the phosphors may degrade when exposed to air.<ref>{{cite journal |last1=Setlur |first1=Anant A. |title=Phosphors for LED-based Solid-State Lighting |journal=The Electrochemical Society Interface |date=1 December 2009 |volume=18 |issue=4 |pages=32–36 |doi=10.1149/2.F04094IF |url=https://www.electrochem.org/dl/interface/wtr/wtr09/wtr09_p032-036.pdf |access-date=5 December 2022 |language=en}}</ref>

===Cathode-ray tubes===<!-- This section is linked from Cathode-ray tube -->
[[File:CRT phosphors.png|thumb|right|400px|Spectra of constituent blue, green and red phosphors in a common cathode-ray tube]]

[[Cathode-ray tube]]s produce signal-generated light patterns in a (typically) round or rectangular format. Bulky CRTs were used in the black-and-white television (TV) sets that became popular in the 1950s, developed into color CRTs in the late 1960s, and used in virtually all color TVs and computer monitors until the mid-2000s. In the late 20th century, advanced electronics made new wide-deflection, "short tube" CRT technology viable, making CRTs more compact, but still bulky and heavy. As the original video display technology, having no viable competition for more than 40 years and dominance for over 50 years, the CRT ceased to be the main type of video display in use only around 2010. In addition to direct-view CRTs, CRT projection tubes were the basis of all projection TVs and computer video projectors of both front and rear projection types until at least the late 1990s.

CRTs have also been widely used in scientific and engineering instrumentation, such as [[oscilloscope]]s, usually with a single phosphor color, typically green. Phosphors for such applications may have long afterglow, for increased image persistence.  A variation of the display CRT, used prior to the 1980s, was the CRT [[storage tube]], a digital memory device which (in later forms) also provided a visible display of the stored data, using a variation of the same electron-beam excited phosphor technology.

The process of producing light in CRTs by electron-beam excited phosphorescence yields much faster signal response times than even modern (2020s) [[LCD]]s can achieve, which makes [[light pen]]s and light gun games possible with CRTs, but not LCDs.  Also in contrast to most other video display types, because CRT technology draws an image by scanning an electron beam (or a formation of three beams) across a phosphor surface, a CRT has no intrinsic "native resolution" and does not require scaling to display raster images at different resolutions; the CRT can display any raster format natively, within the limits defined by the electron beam spot size and, for a color CRT, the dot pitch of the phosphor. Because of this operating principle, CRTs can produce images using either raster and vector imaging methods.  Vector displays are impossible for display technologies that have permanent discrete pixels, including all LCDs, [[Plasma display|plasma display panels]], [[Digital micromirror device|DMD]] projectors, and [[OLED]] (LED matrix, e.g. TFT OLED) panels.

The phosphors can be deposited as either [[thin film]], or as discrete particles, a powder bound to the surface. Thin films have better lifetime and better resolution, but provide less bright and less efficient image than powder ones. This is caused by multiple internal reflections in the thin film, scattering the emitted light.

'''White''' (in black-and-white): The mix of zinc cadmium sulfide and zinc sulfide silver, the {{chem2|ZnS:Ag + (Zn,Cd)S:Ag}} is the white '''P4''' phosphor used in black and white television CRTs. Mixes of yellow and blue phosphors are usual. Mixes of red, green and blue, or a single white phosphor, can also be encountered.

'''Red:''' [[Yttrium]] [[oxide]]-[[sulfide]] activated with europium is used as the red phosphor in color CRTs. The development of color TV took a long time due to the search for a red phosphor. The first red emitting rare-earth phosphor, YVO<sub>4</sub>:Eu<sup>3+</sup>, was introduced by Levine and Palilla as a primary color in television in 1964.<ref>{{cite journal| doi = 10.1063/1.1723611| title = A new, highly efficient red-emitting cathodoluminescent phosphor (YVO<sub>4</sub>:Eu) for color television| year = 1964|author = Levine, Albert K.| journal = Applied Physics Letters| volume = 5|page = 118| first2 = Frank C.| last2 = Palilla|bibcode = 1964ApPhL...5..118L| issue = 6 }}</ref> In single crystal form, it was used as an excellent polarizer and laser material.<ref>{{cite journal| doi = 10.1063/1.98500| title = Highly efficient Nd:YVO<sub>4</sub> diode-laser end-pumped laser| year = 1987|author = Fields, R. A.| journal = Applied Physics Letters| volume = 51|page = 1885| first2 = M.| first3 = C. L.| last2 = Birnbaum| last3 = Fincher|bibcode = 1987ApPhL..51.1885F| issue = 23 | doi-access = free}}</ref>

'''Yellow:''' When mixed with [[cadmium sulfide]], the resulting '''zinc cadmium sulfide''' {{chem2|(Zn,Cd)S:Ag}}, provides strong yellow light.

'''Green:''' Combination of zinc sulfide with [[copper]], the '''P31''' phosphor or {{chem2|ZnS:Cu}}, provides green light peaking at 531&nbsp;nm, with long glow.

'''Blue:''' Combination of zinc sulfide with few ppm of [[silver]], the ZnS:Ag, when excited by electrons, provides strong blue glow with maximum at 450&nbsp;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 (about 100&nbsp;nm) is deposited over the phosphors, usually by vacuum evaporation, 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.

To reduce the image degradation by reflection of ambient light, [[Contrast (vision)|contrast]] can be increased by several methods. In addition to black masking of unused areas of screen, the phosphor particles in color screens are coated with pigments of matching color. For example, the red phosphors are coated with [[ferric oxide]] (replacing earlier Cd(S,Se) due to cadmium toxicity), blue phosphors can be coated with marine blue ([[cobalt(II) oxide|CoO]]·''n''[[alumina|{{chem|Al|2|O|3}}]]) or [[ultramarine]] ({{chem|Na|8|Al|6|Si|6|O|24|S|2}}). Green phosphors based on ZnS:Cu do not have to be coated due to their own yellowish color.<ref name="advelectr">{{cite book|author=Peter W. Hawkes |title=Advances in electronics and electron physics |url=https://books.google.com/books?id=FE_Hvcbkpa4C&pg=PA350 |access-date=9 January 2012 |date=1 October 1990 |publisher=Academic Press |isbn=978-0-12-014679-6 |pages=350–}}</ref>

====Black-and-white television CRTs====
The black-and-white television screens require an emission color close to white. Usually, a combination of phosphors is employed.

The most common combination is {{chem2|ZnS:Ag + (Zn,Cd)S:Cu,Al}} (blue + yellow). Other ones are {{chem2|ZnS:Ag + (Zn,Cd)S:Ag}} (blue + yellow), and {{chem2|ZnS:Ag + ZnS:Cu,Al + Y2O2S:Eu(3+)}} (blue + green + red – does not contain cadmium and has poor efficiency). The color tone can be adjusted by the ratios of the components.

As the compositions contain discrete grains of different phosphors, they produce image that may not be entirely smooth. A single, white-emitting phosphor, {{chem2|(Zn,Cd)S:Ag,Au,Al}} overcomes this obstacle. Due to its low efficiency, it is used only on very small screens.

The screens are typically covered with phosphor using sedimentation coating, where particles [[suspension (chemistry)|suspended]] in a solution are let to settle on the surface.<ref name="lumdisp">Lakshmanan, p. 54.</ref>

====Reduced-palette color CRTs====
For displaying of a limited palette of colors, there are a few options.

In [[penetron|'''beam penetration tubes''']], different color phosphors are layered and separated with dielectric material. The acceleration voltage is used to determine the energy of the electrons; lower-energy ones are absorbed in the top layer of the phosphor, while some of the higher-energy ones shoot through and are absorbed in the lower layer. So either the first color or a mixture of the first and second color is shown. With a display with red outer layer and green inner layer, the manipulation of accelerating voltage can produce a continuum of colors from red through orange and yellow to green.

Another method is using a mixture of two phosphors with different characteristics. The brightness of one is linearly dependent on electron flux, while the other one's brightness saturates at higher fluxes—the phosphor does not emit any more light regardless of how many more electrons impact it. At low electron flux, both phosphors emit together; at higher fluxes, the luminous contribution of the nonsaturating phosphor prevails, changing the combined color.<ref name="lumdisp"/>

Such displays can have high resolution, due to absence of two-dimensional structuring of RGB CRT phosphors. Their color palette is, however, very limited. They were used e.g. in some older military radar displays.

====Color television CRTs====
{{missing information|section|time period of each phosphor composition|date=October 2020}}
The phosphors in color CRTs need higher contrast and resolution than the black-and-white ones. The energy density of the electron beam is about 100 times greater than in black-and-white CRTs; the electron spot is focused to about 0.2&nbsp;mm diameter instead of about 0.6&nbsp;mm diameter of the black-and-white CRTs. Effects related to electron irradiation degradation are therefore more pronounced.

Color CRTs require three different phosphors, emitting in red, green and blue, patterned on the screen. Three separate electron guns are used for color production (except for displays that use [[beam-index tube]] technology, which is rare). The red phosphor has always been a problem, being the dimmest of the three necessitating the brighter green and blue electron beam currents be adjusted down to make them equal the red phosphor's lower brightness. This made early color TVs only usable indoors as bright light made it impossible to see the dim picture, while portable black-and-white TVs viewable in outdoor sunlight were already common.

The composition of the phosphors changed over time, as better phosphors were developed and as environmental concerns led to lowering the content of cadmium and later abandoning it entirely. The {{chem2|(Zn,Cd)S:Ag,Cl}} was replaced with {{chem2|(Zn,Cd)S:Cu,Al}} with lower cadmium/zinc ratio, and then with cadmium-free {{chem2|ZnS:Cu,Al}}.

The blue phosphor stayed generally unchanged, a silver-doped zinc sulfide. The green phosphor initially used manganese-doped zinc silicate, then evolved through silver-activated cadmium-zinc sulfide, to lower-cadmium copper-aluminium activated formula, and then to cadmium-free version of the same. The red phosphor saw the most changes; it was originally manganese-activated zinc phosphate, then a silver-activated cadmium-zinc sulfide, then the europium(III) activated phosphors appeared; first in an [[yttrium vanadate]] matrix, then in [[yttrium oxide]] and currently in [[yttrium oxysulfide]]. The evolution of the phosphors was therefore (ordered by B-G-R):
* {{chem2|ZnS:Ag}}&nbsp;&ndash;&nbsp;{{chem2|Zn2SiO4:Mn}}&nbsp;&ndash;&nbsp;{{chem2|Zn3(PO4)2:Mn}}
* {{chem2|ZnS:Ag}}&nbsp;&ndash;&nbsp;{{chem2|(Zn,Cd)S:Ag}}&nbsp;&ndash;&nbsp;{{chem2|(Zn,Cd)S:Ag}}
* {{chem2|ZnS:Ag}}&nbsp;&ndash;&nbsp;{{chem2|(Zn,Cd)S:Ag}}&nbsp;&ndash;&nbsp;{{chem2|YVO4:Eu(3+)}} (1964&ndash;?)
* {{chem2|ZnS:Ag}}&nbsp;&ndash;&nbsp;{{chem2|(Zn,Cd)S:Cu,Al}}&nbsp;&ndash;&nbsp;{{chem2|Y2O2S:Eu(3+)}} or {{chem2|Y2O3:Eu(3+)}}
* {{chem2|ZnS:Ag}}&nbsp;&ndash;&nbsp;{{chem2|ZnS:Cu,Al}} or {{chem2|ZnS:Au,Cu,Al}}&nbsp;&ndash;&nbsp;{{chem2|Y2O2S:Eu(3+)}}<ref name="lumdisp"/>

====Projection televisions====
For [[projection television]]s, where the beam power density can be two orders of magnitude higher than in conventional CRTs, some different phosphors have to be used.

For blue color, {{chem2|ZnS:Ag,Cl}} is employed. However, it saturates. {{chem2|(La,Gd)OBr:Ce,Tb(3+)}} can be used as an alternative that is more linear at high energy densities.

For green, a [[terbium]]-activated {{chem2|Gd2O2Tb(3+)}}; its color purity and brightness at low excitation densities is worse than the zinc sulfide alternative, but it behaves linear at high excitation energy densities, while zinc sulfide saturates. However, it also saturates, so {{chem2|Y3Al5O12:Tb(3+)}} or {{chem2|Y2SiO5:Tb(3+)}} can be substituted. {{chem2|LaOBr:Tb(3+)}} is bright but water-sensitive, degradation-prone, and the plate-like morphology of its crystals hampers its use; these problems are solved now, so it is gaining use due to its higher linearity.

{{chem2|Y2O2S:Eu(3+)}} is used for red emission.<ref name="lumdisp"/>