title: Full down-conversion of amber-emitting phosphor-converted light-emitting diodes with powder phosphors and a long-wave pass filter.
abstract: 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.
authors.affiliation: Department of Chemistry, Kookmin University, Seoul 136-702, Korea.
authors.forename: Jeong Rok
authors.initials: JR
authors.lastname: Oh
authors.forename: Sang-Hwan
authors.initials: SH
authors.lastname: Cho
authors.forename: Hoo Keun
authors.initials: HK
authors.lastname: Park
authors.forename: Ji Hye
authors.initials: JH
authors.lastname: Oh
authors.forename: Yong-Hee
authors.initials: YH
authors.lastname: Lee
authors.forename: Young Rag
authors.initials: YR
authors.lastname: Do
mesh_terms: D003116:Color; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005374:Filtration / Q000295:instrumentation*; D008027:Light; D008029:Lighting / Q000295:instrumentation*; D011208:Powders; D012666:Semiconductors
chemical_list: D011208:Powders