Enhancement of luminescence properties of SrTiO3:Sm3+ nanophosphor by charge compensator Li+ ion

In the current article, strontium titanate (ST) phosphor material doped with 1-9 mol% samarium ion (Sm3+) is prepared by facile solution combustion route. Characterizations for the prepared sample was carried out via powder X-ray diffraction, scanning and transmission electron microscopy, ultraviolet visible and Fourier transform infrared spectroscopy. Photoluminescence (PL) emission and excitation spectra were studied to examine the luminescence property of ST: Sm3+ nanophosphor. The ST: Sm3+ phosphor emission spectra were credited to the intra 4f orbital transition from the (4)G(5/2) level to the H-6(j) = 5/2, 7/2, and 9/2). The presence of co-doped Li+ ion nanophospor increases the emission intensity of orange-red emission to multiple times. The improvement in the intensity of emission is attributed to the neighborhood symmetry around the Sm3+ and expansion in the crystallattice. The mechanism of PL enhancement in ST: Sm3+ nanophosphor with Li+ ion co-doping is discussed in detail. The optimized concentration of Sm3+ ions chromaticity coordinates were determined to be x = 0.59, y = 0.4. This favors in warm orange-red light emissive display applications.