Enhanced orange-red emission from KSrVO₄:Sm³⁺ nanophosphor for possible application in blue light-emitting diode based white LED

In this paper, the combustion synthesis and photoluminescence properties of Sm³⁺ doped KSrVO₄ nanophosphors are reported. The samples were characterized by different techniques such as x-ray powder diffraction, transmission electron microscopy,UV-vis spectrophotometry and photoluminescence spectroscopy. The lattice parameterswere calculated as a = 7.4688 (4) Å,b = 5.8171 (4) Å, c = 9.9490 (5) Å and V = 432.2485 (5) Å 3. The average grain size of the samples was estimated as 42 nmusing the modified Scherrer's equation. Under near UV excitation, the sharp emission line at 560, 600, 646 and 704 nmdue to characteristic transitions of Sm³⁺ were observed. The maximum PL emission intensity was observed at 1.5 mol.% of theSm³⁺ ions. The band gap of the phosphor was calculated from diffused reflectance data and was found to be 3.74 eV. The CIE 1931 chromaticity coordinates (x, y) of the phosphor were (0.61, 0.39), in a shade of orange-red color. The potential applications of this material as a down conversion phosphor under blue light excitation were evaluated for possible application as a high color-purity phosphor in light emitting diodes (LEDs) that can fill the 590-600 nmgap.