Luminescence studies on Al4B2O9:Eu2+ phosphor crystals.

A novel blue-emitting phosphor, Eu(2+)-doping Al(4)B(2)O(9), was prepared via a modified solid-state reaction. Al(4)B(2)O(9):Eu(2+) nanoparticles with diameters varying in a range from 20 to 50 nm were obtained using urea as an auxiliary reagent at the optimum temperature of 850°C. The crystallization and particle sizes of Al(4)B(2)O(9):Eu(2+) were investigated using powder X-ray diffraction (XRD) and transmission electron microscopy (TEM). Photoluminescence (PL) results showed that Al(4)B(2)O(9):Eu(2+) phosphor could be efficiently excited by the ultraviolet region from 240 to 410 nm, exhibiting bright blue emission. Further investigation on concentration-dependent emission spectra indicated that the Al(3.997) B(2)O(9):Eu(2+)(0.003) phosphor exhibited the strongest luminescent, and the relative PL intensity decreased with increasing Eu(2+) concentration due to concentration quenching. In addition, the concentration quenching for the one-Eu-site emission centers was caused by the electric multipole-multipole interaction.