Synthesis and characterization of La2(WO4)3 nanophosphors via chemical precipitation method

Abstract

Nanocrystalline lanthanum tungstate phosphors were synthesized by direct chemical precipitation route. Thermal, structural and optical properties of the prepared sample were analyzed using different characterization techniques. The thermal behaviour of the sample was studied using thermogravimetric analysis and differential thermal analysis. The prepared sample was found to be crystalline above 6100C. The structural properties were analyzed using X-ray diffraction patterns and field emission scanning electron microscopy images. The lanthanum tungstate nanocrystals show a monoclinic scheelite type structure with C2/c space group. Pebble-like surface morphology of the sample is revealed from FESEM images. UV visible absorption spectroscopy and photoluminescence spectroscopy were used to study its optical properties. The luminescent properties show a bluish-green emission for lanthanum tungstate. Results of the present study confirm that La2(WO4)3 nanophosphors can be used for the construction of near-ultraviolet light excited light-emitting diodes.