Structural and photoluminescence properties of a novel green emitting Tb3+ doped Ba3La2 (BO3)4 phosphor

Abstract

A novel green light emission from rare earth ion Tb3+ at various concentrations of (0.02, 0.04, 0.06, 0.08 and 0.1 mol) doped in barium lanthanum borate (Ba3La2(BO3)4) phosphors have been synthesized by conventional solid state reaction method. The crystal structure, functional and luminescence properties were characterized by XRD, FTIR and Photoluminescence (PL) analyses respectively. Surface morphology and composition of the starting elements of the phosphors were analyzed by FESEM and EDX. From XRD, it was confirmed that an orthorhombic crystal structure for Tb3+ doped Ba3La2 (BO3)4 phosphors. From FTIR, the energy absorption bonds between B-O and B-O-B were identified. From PL study, the emission spectra containing of four emission peaks at 487 nm, 545 nm, 586 nm and 622 nm corresponding to the electronic transitions of 5D4 → 7F6,5D4 → 7F5,5D4 → 7F4 and 5D4 → 7F3 were recorded at NUV excitation of 271 nm. A prominent green emission with high intensity of wavelength at 545 nm corresponding to 5D4 → 7F5 transition was also observed. The CIE colour coordinates of the optimum emission of Ba3La2-x (BO3)4: xTb3+ phosphors were x = 0.2765 and y = 0.6948, which were located in the green region and hence this phosphor might be a potential application in green light emitting display devices.