Alkaline-earth oxide network modifier on optical properties of Ce3+-activated borogermanate glasses

• Ce3+-activated borogermanate glasses modified by alkaline-earth oxides were prepared.
• The MgO glass with the lowest density is the highest emission intensity.
• The BaO glass with the highest density is the lowest emission intensity.
• The best thermal stability is the BaO glass by temperature-dependent emission spectra.

Transparent and colorless CeO2-activated borogermanate glasses, with the nominal composition of 25B2O3–40GeO2–14Gd2O3–1CeO2–20MO (M = Ba, Sr, Ca and Mg), were synthesized by a melt-quenching method in air. Their optical properties including the transmittance, photoluminescence (excitation and emission spectra), the luminescence decay curves, as well as the temperature-dependent emission spectra were studied in detail. The room temperature photoluminescence spectra reveal that the emission intensity of the MgO glass is about two times stronger than that of the BaO glass. The blue shift of the cut-off edge, excitation and emission spectra of Ce3+-activated borogermanate glass were clearly observed in the order of BaO, SrO, CaO and MgO. And the emission intensity of Ce3+ ions as a function of temperature range in 325–475 K was also investigated.