Investigation of color tunability of Dy3+& Eu3+ Co-doped bismuth borate glasses for lighting applications

This study concentrates on energy transfer between rare-earth ions in bismuth borate glasses. The LiBBiEu3+, LiBBi:Dy3+, and co-doped LiBBiDy15Eu20 glasses were synthesized by melt-quenching process and carried out their structural, physical, optical, and luminescence investigations. The photoluminescence (PL)-emission spectra of LiBBi:Eu3+ glass show intense red emission while those of LiBBi:Dy3+ exhibit blue (F-4(9/2) -> H-6(15/2)) and yellow (F-4(9/2 )-> H-6(13/2)) emission under different excitation wavelengths. The co-doped LiBBiDy15Eu20 host glass shows improved red emission, indicating transfer of energy from Dy3+ to Eu3+ ions. The efficiency of energy transfer from Dy3+ to Eu3+ in host glass was determined from PL-emission intensities. The lifetime measurement was employed for single and co-doped glasses under different excitation and emission wavelengths. The lifetime of co-doped sample measured under different excitation and emission wavelengths, confirms energy transformation from Dy3+ to Eu3+ ions. The CIE coordinates indicate that the prepared glass can be employed as red and orange red light-emitting diodes (LEDs) in lighting application.