1Department of Physics, Government Junior College, Sathupally, Khammam District, A. P. 507303, India
2Department of Physics, Rajiv Gandhi University Knowledge Technologies, IIIT, Basara 504101, AP, India
3Display Materials Laboratory, Applied Physics Department, Faculty of Technology and Engineering, M. S. University of Baroda, Baroda 390001, India
Adv. Mater. Lett., 2014, 5 (12), pp 722-727
Publication Date (Web): Dec 02, 2014
Copyright © IAAM-VBRI Press
Pure LaPO4 and LaPO4: Eu (0.5 mol %) Ce (0.5 mol %) phosphors were synthesized by the solid-state reaction method. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), photoluminescence (PL) spectra and the particle size analysis were used to characterize these samples. The XRD results reveal that the synthesized LaPO4:Eu (0.5 mol%) Ce (0.5 mol%) phosphors are well crystalline and assigned to the monoclinic structure with a main (120) diffraction peak. The calculated crystallite size of pure LaPO4 and LaPO4:Eu, Ce phosphors were 67.6nm and 64nm respectively. Upon excitation at 254nm wavelength, the emission spectrum of pure LaPO4 phosphor emits a maximum intensity peak at 470 (blue) nm. In the emission spectrum of LaPO4:Eu3+Ce3+ phosphor, the low contributions of the red (613nm) 5D0-7F2 emissions and the high intensity of the orange-red (589nm)5D0-7F1 emission results in high color purities.The most intense emissions appearing in the 580-620nm region is responsible for the strong orange-red luminescence observed in the Eu,Ce doped LaPO4 phosphor whose CIE colour coordinates are x = 0.57 and y = 0.43.Thus the prepared phosphors can be used as an orange-red emitting material in the field of illuminations and display devices.
Photoluminescence, XRD, SEM, FTIR,phosphor, rare-earth ions,solid state reaction technique, CIE, particle size analysis