Cerium and samarium codoped lithium aluminoborate glasses for white light emitting devices

• XRD spectra show amorphous nature of the prepared glass samples.
• Composition-structural / optical property correlations are discussed.
• The density of glasses increases and corresponding molar volume decreases with an increase in samarium concentration.
• BO4 groups increase at the expense of BO3 groups with the addition of samarium.
• The fluorescence spectra depict an energy transfer from cerium to samarium ions along with simultaneous presence of red, green and blue emissions which can be useful for white light emitting devices.

Cerium and samarium codoped lithium aluminium borate glasses are prepared by using conventional melt quench technique and their structural and spectroscopic analysis has been done. The structural studies have been done using XRD, FTIR and density measurements. The spectroscopic analysis has been done using UV–Vis absorption spectra and fluorescence emission spectra by exciting the glass samples at 380 nm and 400 nm. XRD confirms the amorphous nature of the prepared samples. The density shows an increasing trend with addition of cerium at the expense of aluminium, other components being constant. This is also confirmed by FTIR study which shows the conversion of trigonal BO3 units into more stable tetrahedral BO4 units. The UV–Vis absorption spectra shows an increase in intensity and a significant shift of the optical absorption edge from UV to partially visible region when cerium is added in the pure samarium containing lithium aluminium borate glass. The fluorescence spectra indicate an energy transfer from Ce3+ to Sm3+ ions. Moreover, some of the glass compositions may be found suitable for white light emitting devices as there is a simultaneous presence of red, green and blue emission.