Near White Light Emission and Concentration Quenching of Calcium Titanate Doped with Dysprosium (III) Phosphors.

This paper reports the preparation of CaTiO3 doped with various concentrations of Dysprosium (II) using solid state reaction technique. X-ray diffraction patterns of the sample were taken. Observed XRD pattern was matched using software match2!. The pattern was matched significantly with the crystallographic open database card (COD - 96-101-1212) which is a standard card for CaTiO3 . This matching exhibited that, the prepared sample is cubic in structure with space group P m - 3 m (221). Photoluminescence (PL) studies of the samples were also done. PL intensity was found increasing with increasing dopant concentration and maximum intensity was noted at 2.0 mol% concentration of Dy3+ , thereafter concentration quenching occurred. Emission Peaks were centered at 483 nm (4 F9/2 ➔6 H15/2 ) and 576 nm (4 F9/2 ➔6 H13/2 ) respectively. For studying the concentration quenching, the critical distance for energy transfer and electric multipolar character were estimated. The value of multipolar character expressed that, the transition in emission spectra is a dipole - dipole (d-d) transition. Commission Internationale de l'Éclairage (CIE) coordinates was found as (0.36, 0.39), which is near to white light. Colour Correlated Temperature (CCT) was 4489 K which was indicative of cool appearance of the light emitted.