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

Abstract

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 380nm and 400nm. 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.