Intense red and cyan luminescence in europium doped silicate glasses

The photoluminescence properties of silicate glasses, singly doped with europium ions and co-doped with europium ions and Al powder, have been characterized by the absorption, excitation, and emission spectroscopies. The absorption edge in the absorption spectra shows a large red shift from 320 nm to 405 nm. Under near-ultraviolet (NUV) excitation, sample, doped with Eu³⁺ emit intense red light while those co-doped with Eu³⁺ and Al give intense cyan emission. The influences of the glass compositions on the spectroscopic properties are also discussed. These glasses may be potential candidates for light-emitting diodes (LEDs).