Improvement of phosphor modeling based on the absorption of Stokes shifted light by a phosphor

Abstract

We have found that the emission spectrum of phosphors measured in the powder state differs from that measured for a single phosphor. When the emission spectrum of the powder state is adopted in an optical simulation, the simulated optical properties e.g., the correlated color temperature, color rendering index, and chromaticity coordinates, show a remarkable discrepancy from those of the fabricated LED package. However, the discrepancy is significantly improved when the emission spectrum from a low concentration of phosphor in a silicone binder is employed. We suggest that the discrepancy originates from the absorption of Stokes shifted light by a phosphor.

The luminescence properties of Sr2–1.5x−1.5yP2O7:xDy3+,yCe3+ phosphor for near‐UV‐based white LEDs synthesized by a chemical co‐precipitation method

“…Last but not least, as shown in Figure and Figure , emission and excitation spectra of Sr 2 P 2 O 7 :Ce 3+ phosphor show a significant Stokes shift about 6598.97 cm −1 . We suggest that the distortion in the Ce 3+ emission spectra originates from the re‐absorption effect of Stokes shifted light by nearby aggregated phosphor particles . All above signify that Ce 3+ can randomly enter one distinct site or two luminescence sites in the Sr 2 P 2 O 7 host lattice , and that Sr1 and Sr2 are both appropriate crystallographic sites available for Ce 3+ doping.…”

Acquiring higher lumen efficacy and color rendering index with green NaYF4:Er3+Yb3+ and red α-SrO·3B2O3:Sm2+ layers for designing remote phosphor LED

“…In this design, the reflection cup is filled with the QDs and placed closely to the LED chip, leading to the high optical energy density pressing on QDs. The second approach is seperating the QDs and phosphor materials, similar to the phosphor layers in remote pc-LEDs package [19,20]. The QDs film will be placed far from the LED chip, and as a result, the optical power density has little effect on the QDs.…”

The application of double-layer remote phosphor structures in increasing WLEDs color rendering index and lumen output

“…White light are often a product of combination between blue light from and yellow light from distinct light sources. The idea may be similar but the benefits that LEDs configuration and the set up phosphor layers bring to the luminous efficiency, and the color quality is significant [4][5][6][7][8]. Besides, many other options to coat phosphor such as dispersed coating and conformal coating were presented to produce LEDs, however, fail to replicate the equivalent effect [9,10].…”