TELKOMNIKA Telecommunication, Computing, Electronics and Control
The application of dual-layer remote phosphor geometry in achieving higher color quality of WLEDs

TELKOMNIKA Telecommunication, Computing, Electronics and Control
The application of dual-layer remote phosphor geometry in achieving higher color quality of WLEDs

Color uniformity
Dual-layer remote phosphor
geometry
Luminous flux
Mie-scattering theory
WLEDs

If remote phosphor structures are put into comparison with conformal
phosphor or in-cup phosphor, their luminous flux are better, but the color
quality is not as elevated. This leads to an obvious need of a practical
solution to enhance color quality. Therefore, many studies were carried out to
achieve this purpose, and so is ours. We proposed using two layers of
phosphor in WLEDs to achieve better rendering ability and chromatic
performance. The identical WLEDs with different color temperatures, 5600
K-8500 K, were used and reported in this paper. Our research consists of two
parts, which are placing a layer of red phosphor SrwFxByOz:Eu2+,Sm2+ on the
yellow YAG:Ce3+ phosphor layer at first, and then specifying an appropriate
SrwFxByOz:Eu2+,Sm2+ concentration to reach the highest color performance. It
is shown that with the contribution of SrwFxByOz:Eu2+,Sm2+
, the color
rendering index (CRI) and color quality scale (CQS) are increased. This can
be explained by the increased amount of red light components in the WLEDs
when the concentration of SrwFxByOz:Eu2+,Sm2+ was greater. However,
excessive SrwFxByOz:Eu2+,Sm2+ will cause the reduction in the flux, which
has been proven by the application of Mie scattering and the Lambert-Beer
law. Therefore, the conclusion will present an optimal amount of
SrwFxByOz:Eu2+,Sm2+ to obtain high color quality while minimizing the light loss.

My Hanh Nguyen Thi, Phung Ton That, Hoang Van Ngoc

http://journal.uad.ac.id/index.php/TELKOMNIKA

Sept 5, 2020

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