Preparation and luminescence properties of Dy3+-doped Na3Gd(PO4)2 nanophosphor for solid state white LEDs

Abstract White emitting Na 3 Gd(PO 4 ) 2 nanocrystalline phosphors doped with trivalent dysprosium (Dy 3+ ) ions were synthesized by using citrate gel combustion technique. The structure of the compound is found to be orthorhombic with a particle size is 10 nm. Luminescence properties have been characterized using photoluminescence (PL), excitation, emission spectra and decay time measurements. In emission spectrum sharp emission peaks were observed 4 F 9/2 → 6 H 15/2 (blue) and 4 F 9/2 → 6 H 13/2 (yellow) transition of Dy 3+ ions. From the concentration dependent PL studies, the optimum concentration of Dy 3+ ions in Na 3 Gd(PO 4 ) 2 is found to be 1.0 mol %, where intense near white light for 352 nm pump wavelength. The yellow to blue intensity ratios, CIE chromaticity coordinates and correlated color temperature studies has shown the possibility of using this phosphor for W-LEDs