Investigations of enhanced luminescence properties of Sm3+ doped LaAlO3 nanophosphors for field emission displays

Abstract

LaAlO3: Sm3+ (1-9 mol%) nanophosphors were synthesized using solution combustion synthesis technique. The structural analysis is carried out using different analytical techniques such as Powder X-Ray Diffraction (PXRD), Fourier Transform InfraRed spectra (FTIR), Scanning Electron Microscopy (SEM), transmission electron microscopy (TEM). The bandgap is found to be in the range 4.9-5.3 eV. Photoluminescence and cathodoluminescence spectra are studied for the investigation of the optical property of the synthesized nanoparticles. The pure rhombohedral phase is obtained after calcination at 900 °C. The agglomerated porous structure is revealed from SEM images of the nanoparticles. Under the 406 nm excitation wavelength and 10 keV accelerating voltage the PL and CL spectra are observed with characteristic emission peaks of Sm3+ ions from 4G5/2 to 6HJ=5/2,7/2,9/2 transitions with yellowish-orange color. The CIE coordinates confirm the emission of yellowish-orange luminescence from LaAlO3: Sm3+ phosphors. The results obtained reveal that these materials are potential candidates for the fabrication of field emission displays, photoluminescence liquid crystal displays, and other optical devices.