title: Enhanced luminescence and white light emission from Eu(3+) -co-doped K3 Ca2 (SO4 )3 Cl:Dy(3+) phosphor with near visible ultraviolet excitation for white LEDs.
abstract: The luminescent properties of europium (Eu)- and dysprosium (Dy)-co-doped K3 Ca2 (SO4 )3 Cl halosulfate phosphors were analyzed. This paper reports the photoluminescence (PL) properties of K3 Ca2 (SO4 )3 Cl microphosphor doped with Eu and Dy and synthesized using a cost-effective wet chemical method. The phosphors were characterized by X-ray diffraction and scanning electron microscopy. The CIE coordinates were calculated to display the color of the phosphor. PL emission of the prepared samples show peaks at 484 nm (blue), 575 nm (yellow), 594 nm (orange) and 617 nm (red). The emission color of the Eu,Dy-co-doped K3 Ca2 (SO4 )3 Cl halophosphor depends on the doping concentration and excitation wavelength. The addition of Eu in K3 Ca2 (SO4 )3 Cl:Dy greatly enhances the intensity of the blue and yellow peaks, which corresponds to the (4)  F9/2  → (6) H15/2 and (4)  F9/2  → (6) H13/2 transitions of Dy(3+) ions (under 351 nm excitation). The Eu(3+) /Dy(3+) co-doping also produces white light emission for 1 mol% of Eu(3+) , 1 mol% of Dy(3+) in the K3 Ca2 (SO4 )3 Cl lattice under 396 nm excitation, for which the calculated chromaticity coordinates are (0.35, 0.31). Thus, K3 Ca2 (SO4 )3 Cl co-doped with Eu/Dy is a suitable candidate for NUV based white light-emitting phosphors technology.
authors.affiliation: Department of Physics, Janata Mahavidhyalaya, Chandrapur, 442401, India.
authors.forename: N
authors.initials: N
authors.lastname: Baig
authors.forename: N S
authors.initials: NS
authors.lastname: Dhoble
authors.forename: K
authors.initials: K
authors.lastname: Park
authors.forename: N S
authors.initials: NS
authors.lastname: Kokode
authors.forename: S J
authors.initials: SJ
authors.lastname: Dhoble
mesh_terms: D002133:Calcium Sulfate / Q000737:chemistry; D004419:Dysprosium / Q000737:chemistry*; D005063:Europium / Q000737:chemistry*; D008029:Lighting / Q000295:instrumentation; D049449:Luminescence; D049408:Luminescent Agents / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D013056:Spectrophotometry, Ultraviolet; D014961:X-Ray Diffraction
chemical_list: D049408:Luminescent Agents; D004419:Dysprosium; D005063:Europium; D002133:Calcium Sulfate
keywords: halophosphor; microphosphor; photoluminescence; rare earth; white light