1. Drying Control Additive: DMF
Fluorescence Yield in Sol-gel Materials doped with Rare Earth Impurity Ions
Professors Dan Boye (Davidson College Physics Department)
and Ann Silversmith (Hamilton College Physics Department)
Drying Control Additive: DMF
Full Densification Eliminates
Rehydration Quenching
5D3 emission from Tb3+ (0.02%Tb and 2%Al in SiO2 glass) is sensitive to the presence of water in the glass. The inclusion of a drying additive (dimethyl formamide, DMF) displaces the water created during the hydrolysis reaction. This removes a non-radiative pathway and so the 5D3 emission is greatly enhanced.
5D3:5D4 ratio
0.2%Al and
DMF
0.2%Al
no Al
5D3 7FJ
5D4 7FJ
The drying agent also provides for a more uniform pore distribution. Internal strains are greatly reduced, allowing full densification of the glass with heat treatment. Water cannot re-enter glass and quench 5D3 emission.