Conversion of cool-to-warm orange-reddish light emitting diode by Sm2O3 addition in magnesium borosilicate glasses

Abstract

The composition of 50SiO2−40B2O3−(10−x)MgO−xSm2O3 (x = 0, 0.5, 1.0, and 1.5) was synthesized using the melt quench technique. All samples are formed the glasses as confirmed by X-ray diffraction. The density and optical band gap are found to be increased with the addition of Sm2O3 (intermediate oxide) in place of MgO (modifier). On the other hand, the refractive index and oxide ion polarizability of the glasses are decreased due to the conversion of non-bridging oxygens into bridging oxygens with higher covalent bonded glasses. Interestingly, the symmetric structural units of SiO2 (Q2 and Q4) increased instead of (Q3 and Q1) with the replacement of MgO by Sm2O3. The CIE coordinates show the emission spectra lie in the reddish-orange region and the SBS-1.5 sample has the lowest CCT value (1858 K), which suggests that this glass can be used for light emitting diode which is sensitive for the human eye.