Ce:LYSO, from scintillator to solid-state lighting as a blue luminescent concentrator

• Published in: Scientific reports Vol. 13; no. 1; p. 7199
• Main Authors: Lopez, Lisa, Pichon, Pierre, Loiseau, Pascal, Viana, Bruno, Mahiou, Rachid, Druon, Frederic, Georges, Patrick, Balembois, François
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 03.05.2023; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/1019; 639/301/1019/1020; 639/301/1019/1020/1089; 639/624/1020; Absorption; Brightness; Cerium; Chemical Sciences; Crystals; Humanities and Social Sciences; Light sources; Lighting; Lutetium; multidisciplinary; Science; Science (multidisciplinary); Spectrum allocation; Yttrium
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-023-32689-z

Cerium-doped lutetium-yttrium oxyorthosilicate (Ce:LYSO) is a well-known single crystal scintillator used in medical imaging and security scanners. Recent development of high power UV LED, matching its absorption band, questions the possibility to use Ce:LYSO in a new way: as LED-pumped solid-state light source. Since Ce:LYSO is available in large size crystals, we investigate its potential as a luminescent concentrator. This paper reports an extensive study of the performance in close relation to the spectroscopic properties of this crystal. It gives the reasons why the Ce:LYSO crystal tested in this study is less efficient than Ce:YAG for luminescent concentration: limited quantum efficiency and high losses coming from self-absorption and from excited-state absorption are playing key roles. However, we demonstrate that a Ce:LYSO luminescent concentrator is an innovative source for solid-state lighting. Pumped by a peak power of 3400 W in quasi-continuous wave regime (40 µs, 10 Hz), a rectangular (1 × 22 × 105 mm 3 ) Ce:LYSO crystal delivers a broadband spectrum (60 nm FWHM) centered at 430 nm. At full output aperture (20 × 1 mm 2 ), it emits a peak power of 116 W. On a squared output surface (1 × 1 mm 2 ) it emits 16 W corresponding to a brightness of 509 W cm –2 sr –1 . This combination of spectrum power and brightness is higher than blue LEDs and opens perspectives for Ce:LYSO in the field of illumination namely for imaging.