Circadian light source based on K.sub.x./sub.Na.sub.1-x./sub.LuS.sub.2./sub.:Eu.sup.2+./sup. phosphor

0492156 - FZÚ 2019 RIV US eng J - Journal Article
Jarý, Vítězslav - Havlák, Lubomír - Bárta, Jan - Rejman, M. - Bystřický, Aleš - Dujardin, C. - Ledoux, G. - Nikl, Martin
Circadian light source based on K_xNa_1-xLuS₂:Eu²⁺ phosphor.
ECS Journal of Solid State Science and Technology. Roč. 7, č. 1 (2018), R3182-R3188. ISSN 2162-8769. E-ISSN 2162-8777
R&D Projects: GA TA ČR(CZ) TG02010056
EU Projects: European Commission(XE) 690599 - ASCIMAT
Institutional support: RVO:68378271
Keywords : led conversion phosphors * luminescence properties * temperature
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 1.795, year: 2018

The presented work describes a functional demonstration device representing the source of white light with tunable color correlated temperature. Tunability is achieved by using two different kinds of excitation diodes (nearUV and blue) in combination with a proper KxNa1-xLuS2:Eu2+ phosphor. Its luminescence due to the Eu2+ 5d-4f allowed transition covers a broad emission region in visible range under both nearUV and blue excitations. The possibility to change the intensity ratio of the excitation diodes yields the changes of the output color correlated temperature. These changes are clearly demonstrated by shifts in the CIE color space, light quality is also quantified and discussed using CRI (color rendering index) and CQS (color quality scale) metrics.
Permanent Link: http://hdl.handle.net/11104/0285715