Near white light emission of Ce3+-, Ho3+-, and Sm3+-doped oxyfluoride silicate glasses.

The Ce3+-, Ho3+-, and Sm3+- single and co-doped oxyfluoride silicate glasses for light emitting diodes are studied. These glasses were prepared by melt quenching method and their optical and structural properties were investigated by absorption spectra, photoluminescence spectra, Commission International de I'Eclairage chromaticity coordinates, X-ray diffraction, and Fourier transform infrared spectra. It is found that the introduction of Al2O3 in glass composition can improve the emissions of Ho3+ and Sm3+. While the presence of B2O3 has the adverse effect and can suppress the emissions of Ho3+ and Sm3+. With substituting Na2O for CaO in the glass compositions, CaF2 crystals can be formed during the melt quenching process. We find the formation of CaF2 crystals can change the emission behavior of Ho3+ and Sm3+ ions. White light emissions can be achieved in the glasses and the luminescence colors can be tuned by varying the concentrations of the doped rare-earth ions and the composition of glass matrix. The Ce3+-, Ho3+-, and Sm3+-doped oxyfluoride silicate glasses presented here demonstrate promising applications in the fields of light emitting diodes. [ABSTRACT FROM AUTHOR]