A benign approach for tailoring the photometric properties and Judd-Ofelt analysis of LaAlO3:Sm3+ nanophosphors for thermal sensor and WLED applications

Sm3+ doped (1-9 mol%) Lanthanum aluminate (LaAlO3) nanophosphor was prepared by solution combustion synthesis and characterized by photoluminescence (PL), powder X-ray diffraction (PXRD), UV-vis (UV-vis), scanning and transmission electron microscopy (SEM and TEM). PL excitation and emission spectra, quantum efficiency, luminescence life time were studied to investigate the luminescence properties of LaAlO3:Sm3+ nanophosphor, effectively excited by near UV wavelength 406 nm. The combination of different coloured emissions in visible region presents a desired white light which leads to the WLED application. The chromaticity coordinates of the optimized concentration of Sm3+ was estimated to be (0.3684, 0.4066) and the corresponding correlated color temperature (CCT) was found to be similar to 4485 K which favors in warm white light emissive display applications. The luminescence quantum efficiency was calculated from the emission spectra using Judd-Ofelt (J-O) theory. From the analysis the estimated branching ratio (similar to 56%) was greater than 50%, as a result the phosphor was highly suitable for display devices. The present phosphor was highly useful as thermal sensor in the temperature interval between 100 to 400 degrees C as estimated from decay time measurements. (C) 2016 Elsevier B.V. All rights reserved.