Investigation of Sm 3+-doped PBNaG glasses for orange LED applications

The doping of a host glass with rare-earth ions is quite interesting when investigating their wide applications in several fields, such as laser and optical fibers. In this study, the glass medium had a composition of (70 − x) P2O5–10Bi2O3–10Na2O–10Gd2O3–xSm2O3 with x = 0, 0.05, 0.1, 0.5, 1.0, 3.0 mol% and were fabricated using melt-quenching method. The optical properties of Sm3+-doped samples with different Sm3+ concentrations were determined by measuring the absorption and luminescence spectra in the visible light region. Both the direct and the indirect bandgap energies were slightly decreased after doping with Sm3+ ions. The maximum experimental oscillator strength was 3.65 × 10–6 for the band transition 6H5/2 → 6F7/2 over glass PBNaGSm5. The Judd–Ofelt parameters were applied to evaluate the properties of glass samples. The highest emission intensity was located in the orange range with a wavelength of 597 nm under an excitation wavelength of 401 nm. An obvious decrease in the lifetime was observed at higher Sm3+ ion concentrations.