FLUORESCENCE PROPERTIES OF ER3-DOPED SOL-GEL GLASSES()

Er3+-doped sol-gel silica was prepared and its fluorescence spectra me asured. The samples were prepared from tetraethoxysilane (TEOS), water and ethanol, using Er(NO3)(3) . 5H(2)O as the Er3+ precursor. Transpa rent gel-glasses were obtained from two synthesis schemes (molar ratio s of TEOS/H2O/C2H5OH = 1/4/4 and 1/16/0) for Er2O3 concentrations rang ing from 0.1 to 10.0 wt%. All samples exhibited visible (S-4(3/2) --> I-4(15/2) and F-4(9/2) --> I-4(15/2)) and infrared fluorescence at roo m temperature, The Er3+ fluorescence intensity was observed to increas e with increasing heat treatment temperature of a sample. The presence of Al3+ led to a broadening and blue shift of the Er3+ I-4(13/2) --> I-4(15/2) fluorescence. These effects are consistent with a more rando m site distribution and a more ionic bonding environment for Er3+ in t he glass.