Physical and optical properties of Dy 3+ /Pr 3+ Co-doped lithium borate glasses for W-LED

Rare earth ions doped glasses have drawn abundant interest among the researchers for their use in various optical and optoelectronic devices. In the present work, physical and optical parameters of lithium borate glasses co-doped with Dy3+ and Pr3+ have been studied for white LED application. The conventional melt quenching technique is used to prepare the glass samples. The amorphous nature of glass samples were confirmed by XRD study. The various functional groups were studied by FTIR spectroscopy. Optical absorption spectra were recorded by UV-VIS-NIR spectroscopy. Allowed direct and indirect energy band gap were obtained by means of Tau's method. Luminescence spectra were carried out at room temperature, spectra shows seven emission bands at various wavelength ranges. An intense emission band is observed at 663 nm (4F9/2 → 6H11/2) due to energy transfer from Pr3+ to Dy3+. The CIE colour co-ordinates were calculated for all glass samples. CIE chromaticity diagram shows glass (G-4), containing 0.6 mol % Pr6O11 with colour co-ordinates X = 0.33 and Y = 0.40 have highest red (663 nm) emission intensity. These glasses having emission very close to white light and thus can be used for white LED application.