Color tunable Eu3+ doped SrWO4 phosphors for solid state lighting

Abstract

The existing work explains the structural and spectroscopic properties of pure and Eu3+ doped SrWO4 phosphor synthesized by solid state reaction method. The prime focus of the work is to examine the photoluminescence behavior of the trivalent europium (Eu3+) doped SrWO4 phosphors for solid state lighting. The structural and spectroscopic properties of the samples were investigated by X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy and photoluminescence spectroscopy (PL). The synthesized sample exhibits the single phase tetragonal structure with space group I41/a, as confirmed by the XRD result. Photoluminescence excitation and emission spectra along with decay kinetics were studied at room temperature for different concentrations of Eu3+ ions. The excitation spectra exhibit strong charge transfer bands at around 258 and 268 nm and relatively less intense peaks at around 318, 362, 382 and 395 nm. The Emission spectra, recorded under 266 nm excitation wavelength exhibits a high intense peak at around 615 nm and some low intense peaks at around 536, 590, 654 and 702 nm. The emission intensity continues to be increasing as the doping percent increases and it becomes maximum at 1 mol% and thereafter intensity decreases with further increase in concentration. The photometric study shows that the color coordinates of the proposed phosphor can be tuned from bluish white region to yellowish orange region and finally orange region by increasing the Eu3+ concentration from 0.25 mol% to 4 mol%. So the prepared samples can be served as a multicolor emitting phosphor material.