Modeling the role of phosphor grain packing in compact fluorescent lamps

Pannier, N.; Filoche, Marcel; Plapp, Mathis; Buissette, Valérie; Mercier, Thierry Le

doi:10.1117/12.893416

Cited by 1 publication

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Other groups propose to control the size of YAG grains to limit light back-scattering. 4 Another method consists of controlling light propagation within the phosphor film to generate light in the desired direction. 5,6 Herein we investigate a different strategy which consists in increasing the phosphor brightness by increasing the Ce doping concentration while ensuring that the internal luminescence quantum yield remains high.…”

Section: Introductionmentioning

confidence: 99%

A strategy to increase phosphor brightness: Application with Ce3+-doped Gd3Sc2Al3O12

Devys

Dantelle²,

Laurita³

et al. 2017

Journal of Luminescence

View full text Add to dashboard Cite

Y3Al5O12 (YAG) doped with Ce 3+ ions is widely used as a phosphor for the generation of white light in LEDs. However, the material presents intrinsic drawbacks: (1) a yellow emission band lacking a red component, leading to a "cold" white light and (2) limited cerium incorporation (~ 3 mol.%), resulting in poor absorption and thus limiting the external quantum efficiency (EQE) of the LED device. In order to increase phosphor absorption and thus phosphor brightness, we propose here an original strategy based on the increase of Ce content in a phosphor compound, while preserving a high internal luminescence quantum yield. For this purpose, we introduce Ce 3+ -doped Gd3Sc2Al3O12 (GSAG:Ce). Gd3(1-x)Ce3xSc2Al3O12 polycrystalline samples were prepared through a solid-state microwave-assisted reaction, with x varying from 0 to 0.5; Ce 3+ ions can be incorporated into the GSAG matrix with a concentration up to approximately x = 0.18 (i.e. 18 mol.%) without the formation of a parasitic phase. The maximum emission wavelength is located at 573 nm for a doping concentration of x = 0.1, giving an orange feature to the emission. The internal luminescence quantum yield (Φ) is 52 % for Ce concentration up to x = 0.03. The EQE, which is proportional to the product of Φ by the Ce concentration when considering a thin transparent phosphor layer is predicted to be about 30 % stronger when using GSAG doped with 10 mol.% Ce (x=0.1), with respect to YAG doped with 2 mol.% Ce (x=0.02).

show abstract

Section: Introductionmentioning

confidence: 99%