Synthesis and photoluminescence properties of Sm3+ doped LiGd(WO4)2 phosphors with high color purity

• Published in: Optical materials 2020-04, Vol.102, p.109804, Article 109804
• Main Authors: Kalimuthu, Kavi Rasu, Moorthy Babu, S., Kalimuthu, Vijayarangamuthu
• Format: Article
• Language: English
• Subjects: Luminescence; Optical properties; Red phosphors; Sol-gel
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2020.109804

A series of Sm3+:LiGd(WO4)2 phosphors with various concentrations of Sm3+ was prepared by the Pechini sol-gel method. The X-ray diffraction pattern of pure and Sm3+:LiGd(WO4)2 samples show the formation of LGW compound with tetragonal phase and a noticeable peaks shift toward lower angle with increasing Sm3+ concentration. The particles were of size 1–2 μm with irregular spherical and rectangular-like mixed morphology were witnessed from the scanning electron microscopy (SEM). X-ray photoelectron spectroscopy (XPS) spectrum of the doped sample depicts the presence of all the elements in the Sm3+ doped LiGd(WO4)2 compound. Board band excitation for CTB and the number of sharp excitation peaks for f-f transition were observed in excitation spectra. The emission spectra show sharp peaks at 562, 606, 645 and 701 nm due to transition from sm3+ ions. The optimal dopant concentration of Sm3+ ions and its critical distance in LiGd(WO4)2 matrix was calculated to be x = 0.01 and 3.0 nm for intense emission peak at 645 nm that corresponds to 4G5/2 → 6H9/2 transition of Sm3+ ions. The type of energy transfer interaction among Sm3+ was found as electric dipole-dipole interaction using the Dexter theory. CIE coordinates and color purity (CP) for reddish-orange emission of the Sm3+:LiGd(WO4)2 phosphors was determined to be (0.568, 0.425) and 82.4%, respectively. The observed properties of Sm3+:LiGd(WO4)2 proves its potential application for near UV based light-emitting diodes and optical display devices. •Sm3+:LGdW novel phosphors were successive prepared via Pechini sol gel method.•Phase purity, particle morphological were analysized using XRD and SEM.•Chemical composition and optical properties were investigation by XPS, UV–Visible and fluorescence spectrophotometer.•CIE and color factor of Sm3+:LGdW phosphors were estimated.