Synthesis and Characterization of Orange-Red Emitting Li4SrCa(SiO4)2: Sm3+ Phosphor for Solid- State Lighting and Dosimetry Application
摘要
The Sm3+ doped phosphor Li4SrCa(SiO4)2 samples were prepared by a high-temperature solid-state method with varying concentrations of Sm3+ ions. All synthesized samples were characterized by Power X-ray diffraction (PXRD), Raman Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray Spectroscopy (EDX), Photoluminescence (PL) Spectrofluorometer, and Thermoluminescence (TL) reader. The X-ray diffraction pattern of the synthesized phosphors is well-matched with the JCPDS-83-0763 file and exhibits a good orthorhombic crystalline nature. The sharp and narrow X-ray diffraction peaks show that the phosphor is in a crystalline single phase with an orthorhombic crystal structure. The morphology and elemental composition of Li4SrCa(SiO4)2:Sm3+ compound was measured and observed by the FESEM and EDX elemental analyzer. The PL spectra of Sm3+ doped Li4SrCa(SiO4)2 phosphor showed orange-red emission with four intense peaks at 564 nm, 599 nm, 646 nm, and 711 nm. The TL studies of Sm3+ doped Li4SrCa(SiO4)2 phosphors were also studied using UV (254 nm) stimulation, calculating kinetics parameters, and evaluation of the TL glow curve by different methods. The activation energy (E) vs. Tstop technique is verified by the existence of overlapping peaks in the TL glow curve. Hence, The PL and TL studies revealed that the prepared Li4SrCa(SiO4)2:Sm3+ phosphor may be suitable for orange-red tunable LEDs for solid-state lighting and dosimetry applications.