title: Spectroscopic and photoluminescence characterization of Dy(3+) in Sr0.5Ca0.5TiO3 phosphor.
abstract: The spectroscopic and photoluminescence characteristics of trivalent dysprosium (Dy(3+))-doped Sr0.5Ca0.5TiO3 phosphor materials synthesized via solid-state reaction method were studied. The X-ray diffraction profile confirmed the orthorhombic perovskite structure of the prepared samples. Judd-Ofelt analysis was carried out to obtain the intensity parameters and predicted radiative properties of Sr0.5Ca0.5TiO3:2wt%Dy(3+). The photoluminescence spectrum of Dy(3+)-doped Sr0.5Ca0.5TiO3 showed three emission peaks at 481, 574 and 638 nm corresponding to (4)F9/2 →(6)H15/2, (4)F9/2 →(6)H13/2 and (4)F9/2 →(6)H11/2 transitions respectively. The variation of luminescence intensity with different excitation wavelengths and Dy(3+) concentrations is discussed. The decay profiles of (4)F9/2 excited levels of Dy(3+) ions show bi-exponential behaviour and also a decrease in average lifetime with increase in Dy(3+) concentration. Yellow to blue luminescence intensity ratio, CIE chromaticity co-ordinates and correlated color temperature were also calculated for different concentrations of Dy(3+)-doped Sr0.5Ca0.5TiO3 phosphor at different λex.
authors.affiliation: School of Pure & Applied Physics, Mahatma Gandhi University, Kottayam, India, 686560.
authors.forename: Viji
authors.initials: V
authors.lastname: Vidyadharan
authors.affiliation: School of Pure & Applied Physics, Mahatma Gandhi University, Kottayam, India, 686560.
authors.forename: E
authors.initials: E
authors.lastname: Sreeja
authors.affiliation: School of Pure & Applied Physics, Mahatma Gandhi University, Kottayam, India, 686560.
authors.forename: Saritha K
authors.initials: SK
authors.lastname: Jose
authors.affiliation: School of Pure & Applied Physics, Mahatma Gandhi University, Kottayam, India, 686560.
authors.forename: Cyriac
authors.initials: C
authors.lastname: Joseph
authors.affiliation: School of Pure & Applied Physics, Mahatma Gandhi University, Kottayam, India, 686560.
authors.forename: N V
authors.initials: NV
authors.lastname: Unnikrishnan
authors.affiliation: School of Pure & Applied Physics, Mahatma Gandhi University, Kottayam, India, 686560.
authors.forename: P R
authors.initials: PR
authors.lastname: Biju
mesh_terms: D002118:Calcium / Q000737:chemistry*; D004419:Dysprosium / Q000737:chemistry*; D049449:Luminescence; D008163:Luminescent Measurements; D010100:Oxygen / Q000737:chemistry*; D055668:Photochemical Processes; D013324:Strontium / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
chemical_list: D004419:Dysprosium; D014025:Titanium; D010100:Oxygen; D002118:Calcium; D013324:Strontium
keywords: CIE co-ordinates; Judd-Ofelt parameters; Sr0.5Ca0.5TiO3; correlated color temperature; perovskite structure; photoluminescence