PHOTOLUMINESCENCE PROPERTIES OF NANOCRYSTALLINE Y_2O_3:Eu~(3+) IN DIFFERENT ENVIRONMENTS

摘要

In this study the optical properties of nanocrystalline europium doped yttria Y_2O_3:Eu~(3+) were investigated in dependence on different environments such as a silica based molecular sieve MCM-41, with a pore sizes of 2.7nm, a free nanopowder on air and in aqueous solution. All these results were compared to a commercial lamp phosphor powder with a grain size of about 5#mu#m. Investigated optical properties are the photoluminescence emission spectra, the excitation spectra, the lifetimes and the quantum efficiencies. Heavy differences of the change transfer process will be reported and discussed with respect to the structure. A low optical quantum efficiency of the nanoparticles is explained by changes in the crystal field.