Alpha-particle-induced luminescence of rare-earth-doped Y2O3 nanophosphors

The feasibility of utilizing Y2O3:Tb3+ and Y2O3:Eu3+ as radioluminescent nanophosphors under alpha-particle excitation is investigated. Materials synthesized by the urea homogeneous precipitation method were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The XRD analysis of as-produced precipitates and nanophosphors fired at temperatures ranging from 950 to 1100 degrees C indicated the presence of highly crystalline cubic Y2O3 with crystallite sizes of similar to 40 run. SEM and TEM analysis revealed that particles with average diameters of similar to 200 nm and comprised of similar to 40 nm grains were obtained. High-resolution radioluminescence and photoluminescence spectra were used to investigate the unwanted radioluminescence saturation effects associated with the high ionization rate of alpha-particles. Additionally, the radioluminescence intensity as a function of rare-earth ion dopant concentration is investigated for these materials under alpha-particle excitation. The prospect for utilizing these materials as intermediate absorbers in indirect-conversion radioisotope batteries is discussed. (C) 2008 Elsevier Inc. All rights reserved.