title: Preparation of balanced trichromatic white phosphors for solid-state white lighting.
abstract: High quality white light-emitting diodes (LEDs) employ multi-component phosphor mixtures to generate light of a high color rendering index (CRI). The number of distinct components in a typical phosphor mix usually ranges from two to four. Here we describe a systematic experimental technique for starting with phosphors of known chromatic properties and arriving at their respective proportions for creating a blended phosphor to produce light of the desired chromaticity. This method is applicable to both LED pumped and laser diode (LD) pumped white light sources. In this approach, the radiometric power in the down-converted luminescence of each phosphor is determined and that information is used to estimate the CIE chromaticity coordinate of light generated from the mixed phosphor. A suitable method for mixing multi-component phosphors is also described. This paper also examines the effect of light scattering particles in phosphors and their use for altering the spectral characteristics of LD- and LED-generated light. This is the only approach available for making high efficiency phosphor-converted single-color LEDs that emit light of wide spectral width.
authors.affiliation: School of Electrical Engineering and Computer Science, Ohio University, Athens, OH 45701, USA.
authors.forename: Sara
authors.initials: S
authors.lastname: Al-Waisawy
authors.affiliation: School of Electrical Engineering and Computer Science, Ohio University, Athens, OH 45701, USA.
authors.forename: Anthony F
authors.initials: AF
authors.lastname: George
authors.affiliation: School of Electrical Engineering and Computer Science, Ohio University, Athens, OH 45701, USA.
authors.forename: Wojciech M
authors.initials: WM
authors.lastname: Jadwisienczak
authors.affiliation: School of Electrical Engineering and Computer Science, Ohio University, Athens, OH 45701, USA.
authors.forename: Faiz
authors.initials: F
authors.lastname: Rahman
mesh_terms: D053844:Lasers, Solid-State; D008027:Light; D008029:Lighting; D049408:Luminescent Agents / Q000138:chemical synthesis / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D014025:Titanium / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
chemical_list: D049408:Luminescent Agents; C009495:titanium dioxide; D012822:Silicon Dioxide; D015040:Zirconium; D014025:Titanium; C028541:zirconium oxide
keywords: chromaticity; light-emitting diodes (LEDs); phosphors; solid-state lighting (SSL); wavelength down-conversion