Structure and Luminescence of Ce-doped Lu_2SiO_5 Nanophosphor

摘要

Nanophosphors correspond to nanostructured inorganic insulator materials that emit light under particle or electromagnetic radiation excitation. In this work we investigate the structure and luminescent properties of Ce-doped Lu_2SiO_5 (LSO) nanophosphors prepared by solution combustion synthesis with the Ce content 0.1 to 12 at.%. Samples were characterized by transmission electron microscopy (TEM), line scan electron energy-loss spectroscopy (EELS), X-ray diffraction (XRD), and electron paramagnetic resonance (EPR) spectroscopy. Photoluminescence excitation and emission spectra are composed of two major bands centered at 360 and 430 nm, respectively. These results reveal a red-shift and enhanced Stokes shift for the nanophosphors when compared to bulk. Ce content was also found to affect photoluminescence emission intensity and fluorescent lifetime. The nanophosphor concentration quenching curve presents a broad maximum centered at 1 at.%. Lifetime measurements show a continuous decrease from 34 to 21 ns as Ce content is increased.