Photoluminescence Studies of Europium Doped Di-Strontium Magnesium Silicate Phosphors

Abstract

This article reports the study of photoluminescence spectra of Di Strontium Magnesium Silicate (Sr2MgSi2O7) doped with various concentration of Europium (Eu3+) prepared using solid-state reaction technique. The doping concentration (s) of Eu3+ were 0.2, 0.5, 1.0, 1.5, 2.0, 2.5 mol% respectively. Excitation spectrum monitored at 620 nm wavelength that exhibited two prominent peaks centered at 256 nm and 277 nm. Peak observed at 277 nm was more intense therefore the emission spectra were monitored at 277. Emission Spectra of all the samples revealed intense peaks centred at 607, 618 and 637 are attributed to 5D0 7F2 of Europium (III) ions accommodated at various lattice sites having different energies. Overall emission was found in the red colour region which was confirmed using a CIE chromaticity diagram with coordinate (0.4805, 0.3763). Critical distance for energy transfer in the concentration, beyond which concentration quenching occurred in PL spectra, was calculated. In this case, the critical distance was found to be 19.87 Å, therefore the mechanism involved in concentration quenching of Sr2MgSi2O7 doped with 2.0 mol % of Europium (III) must be only multipole-multipole exchange whereas the exchange interaction is ineffective.