Editing Gadolinium (section)

===Phosphors===
Gadolinium is used as a phosphor in medical imaging. It is contained in the phosphor layer of [[X-ray]] detectors, suspended in a polymer matrix. [[Terbium]]-[[doping (semiconductors)|doped]] [[gadolinium oxysulfide]] (Gd<sub>2</sub>O<sub>2</sub>S:Tb) at the phosphor layer converts the X-rays released from the source into light. This material emits green light at 540&nbsp;nm because of the presence of Tb<sup>3+</sup>, which is very useful for enhancing the imaging quality. The energy conversion of Gd is up to 20%, which means that one fifth of the X-ray energy striking the phosphor layer can be converted into visible photons.{{citation needed|date=March 2023}} Gadolinium oxyorthosilicate (Gd<sub>2</sub>SiO<sub>5</sub>, GSO; usually doped by 0.1–1.0% of [[Cerium|Ce]]) is a single crystal that is used as a [[scintillator]] in medical imaging such as [[positron emission tomography]], and for detecting neutrons.<ref>{{cite journal|doi= 10.1117/1.1829713|title= Use of gadolinium oxyorthosilicate scintillators in x-ray radiometers|date= 2005 |vauthors= Ryzhikov VD, Grinev BV, Pirogov EN, Onyshchenko GM, Bondar VG, Katrunov KA, Kostyukevich SA |journal= Optical Engineering|volume= 44|pages= 016403|bibcode= 2005OptEn..44a6403R}}</ref>

Gadolinium compounds were also used for making green [[phosphor]]s for color TV tubes.<ref>{{Cite journal |last1=Sajwan |first1=Reena K. |last2=Tiwari |first2=Samit |last3=Harshit |first3=Tulika |last4=Singh |first4=Ajaya Kumar |date=2017-10-10 |title=Recent progress in multicolor tuning of rare earth-doped gadolinium aluminate phosphors GdAlO3 |url=https://www.researchgate.net/publication/320308564 |journal=Optical and Quantum Electronics |language=en |volume=49 |issue=11 |pages=344 |doi=10.1007/s11082-017-1158-5 |s2cid=254897308 |issn=1572-817X}}</ref>