A cyan-green-emitting garnet-structured Lu3-Sc Al2-Sc Al3-Sc O12: Ce3+ phosphor ceramics towards high-color-quality laser-driven lighting

For the laser-driven lighting, traditional phosphor ceramics (PCs), such as Y3Al5O12: Ce3+ (YAG: Ce) PC and Lu3Al5O12: Ce3+ (LuAG: Ce) PC, usually show a wide "cyan cavity" due to the ultra-narrow emission bandwidth (∼2 nm) of the blue laser diode (LD). In this regard, the attainable color rendering (Ra) is always <90 even via the combination of "YAG: Ce/LuAG: Ce + CaAlSiN3:Eu2+". Evidently, the "cyan gap" is the bottleneck issue to attain high-color-quality laser-driven lighting. As such, we develop a novel cyan-green-emitting garnet-structured solid-solution Lu3-xScxAl2-yScyAl3-zSczO12: Ce3+ (abbreviated as LuScAG: Ce) PCs, derived from the LuAG: Ce PC. A comparative study is conducted to unearth its microstructure, luminescence properties and promising availability. It can be found that the LuScAG: Ce PCs shows large full width at half maximum (FWHM) and abundant cyan emission. Upon material optimization, bright cyan-green emission can be generated with internal quantum efficiency (IQE) of 87.4 % and FWHM of 87.17 nm. Remarkably, this new material yields high-power emitting light with luminous flux (LF) of 3230 lm and luminous efficacy (LE) of 89.7 lm/W upon 36.0 W blue LD driven in rotatory excitation mode, which can serve as an efficient laser color converter. As expected, due to the achieved affluent cyan emissive components of developed LuScAG: Ce PCs, the lighting source based on "LuScAG: Ce PC + CASN: Eu phosphor-in-glass film (PiGF)" shows high color quality with Ra of 90.6 and R12 (related with the cyan cavity) of 85.0.