Editing Ultraviolet (section)

===Ultraviolet LEDs===
[[File:UV LED Fluoresence.jpg|thumb|upright|A 380&nbsp;nanometer UV LED makes some common household items fluoresce.]]
[[Light-emitting diodes]] (LEDs) can be manufactured to emit radiation in the ultraviolet range. In 2019, following significant advances over the preceding five years, UVA LEDs of 365&nbsp;nm and longer wavelength were available, with efficiencies of 50% at 1.0&nbsp;W output. Currently, the most common types of UV LEDs are in 395&nbsp;nm and 365&nbsp;nm wavelengths, both of which are in the UVA spectrum. The rated wavelength is the peak wavelength that the LEDs put out, but light at both higher and lower wavelengths are present.<ref>{{cite journal |last1=Bhattarai |first1=Trailokya |last2=Ebong |first2=Abasifreke |last3=Raja |first3=M.Y.A. |title=A Review of Light-Emitting Diodes and Ultraviolet Light-Emitting Diodes and Their Applications |journal=Photonics |date=May 2024 |volume=11 |issue=6 |page=491 |doi=10.3390/photonics11060491 |doi-access=free |bibcode=2024Photo..11..491B }}</ref>

The cheaper and more common 395&nbsp;nm UV LEDs are much closer to the visible spectrum, and give off a purple color. Other UV LEDs deeper into the spectrum do not emit as much visible light.<ref>{{cite web
 |title=What is the difference between 365&nbsp;nm and 395&nbsp;nm UV LED lights?
 |website=waveformlighting.com
 |url=https://www.waveformlighting.com/tech/what-is-the-difference-between-365-nm-and-395-nm-uv-led-lights
 |access-date=2020-10-27
 |archive-date=22 May 2021
 |archive-url=https://web.archive.org/web/20210522101632/https://www.waveformlighting.com/tech/what-is-the-difference-between-365-nm-and-395-nm-uv-led-lights
 |url-status=live
 }}</ref> LEDs are used for applications such as [[UV curing]] applications, charging glow-in-the-dark objects such as paintings or toys, and lights for detecting counterfeit money and bodily fluids. UV LEDs are also used in digital print applications and inert UV curing environments. As technological advances beginning in the early 2000s have improved their output and efficiency, they have become increasingly viable alternatives to more traditional UV lamps for use in UV curing applications, and the development of new UV LED curing systems for higher-intensity applications is a major subject of research in the field of UV curing technology.<ref>{{cite journal |last1=Patil |first1=Renuka Subhash |last2=Thomas |first2=Jomin |last3=Patil |first3=Mahesh |last4=John |first4=Jacob |title=settings Order Article Reprints Open AccessReview To Shed Light on the UV Curable Coating Technology: Current State of the Art and Perspectives |journal=Journal of Composites Science |date=2023 |volume=7 |issue=12 |pages=513 |doi=10.3390/jcs7120513 |doi-access=free }}</ref>

UVC LEDs are developing rapidly, but may require testing to verify effective disinfection. Citations for large-area disinfection are for non-LED UV sources<ref>
{{cite journal
 |last1=Boyce |first1=J.M.
 |year=2016
 |title=Modern technologies for improving cleaning and disinfection of environmental surfaces in hospitals
 |journal=Antimicrobial Resistance and Infection Control
 |volume=5 |issue=1
 |page=10
 |pmid=27069623 |pmc=4827199 |doi=10.1186/s13756-016-0111-x
|doi-access=free
 }}
</ref> known as [[germicidal lamp]]s.<ref name="Liverpool, UVGI" >
{{cite web
 |title=Ultraviolet germicidal irradiation  |page=3
 |publisher=[[University of Liverpool]]
 |url=https://www.liverpool.ac.uk/media/livacuk/radiation/pdf/UV_germicidal.pdf
 |url-status=dead
 |archive-url=https://web.archive.org/web/20160806185506/https://www.liverpool.ac.uk/media/livacuk/radiation/pdf/UV_germicidal.pdf
 |archive-date=2016-08-06
}}
</ref> Also, they are used as line sources to replace [[deuterium lamp]]s in [[HPLC|liquid chromatography]] instruments.<ref>
{{cite news
 |title=UV‑C LEDs Enhance Chromatography Applications
 |website=GEN Eng News
 |url=http://www.genengnews.com/gen-articles/uvc-leds-enhance-chromatography-applications/5880
 |url-status=live
 |archive-url=https://web.archive.org/web/20161104020423/http://www.genengnews.com/gen-articles/uvc-leds-enhance-chromatography-applications/5880
 |archive-date=4 November 2016
}}
</ref>