Full down-conversion of amber-emitting phosphor-converted light-emitting diodes with powder phosphors and a long-wave pass filter.
This paper reports the possibility of a facile optical structure to realize a highly efficient monochromatic amber-emitting light-emitting diode (LED) using a powder-based phosphor-converted LED combined with a long-wave pass filter (LWPF). The capping of a blue-reflecting and amber-passing LWPF enhances both the amber emission from the silicate amber phosphor layer and the color purity due to the blocking and recycling of the pumping blue light from the InGaN LED. The enhancement of the luminous efficacy of the amber pc-LED with a LWPF (phosphor concentration 20 wt%, 39.4 lm/W) is 34% over that of an amber pc-LED without a LWPF (phosphor concentration 55 wt%, 29.4 lm/W) at 100 mA and a high color purity (>96%) with Commission International d'Eclairage (CIE) color coordinates of x=0.57 and y=0.42.
Oh
Jeong Rok
JR
Department of Chemistry, Kookmin University, Seoul 136-702, Korea.
Cho
Sang-Hwan
SH
Park
Hoo Keun
HK
Oh
Ji Hye
JH
Lee
Yong-Hee
YH
Do
Young Rag
YR
D003116:Color; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005374:Filtration / Q000295:instrumentation*; D008027:Light; D008029:Lighting / Q000295:instrumentation*; D011208:Powders; D012666:Semiconductors
D011208:Powders