Structural and optical properties of Dy3+-doped lithium borate glass

The ratio between the network modifier Li2O and the network former B2O3 has a significant influence on the structural and optical properties of Dy3+-doped lithium borate glass. Differential scanning calorimetry shows that upon increasing the modifier-to-former ratio (Li2O-to-B2O3) in favour of Li2O, the glass transition temperature increases up to a maximum value of 502°C for the 1:3 sample, while the crystallization temperature decreases linearly from 653 to 534°C. Raman spectroscopy confirms the highest network connectivity for the glass with a modifier-to-former ratio of 1:3. Under ultraviolet excitation, Dy3+ shows emission lines in the visible spectral range, the most intense ones at 484 and 575 nm. The absolute photoluminescence quantum efficiency is best for the glass with a modifier-to-former ratio of 1:6.