Luminescence properties of a novel green emitting Ba2CaZn2Si6O17:Eu2+ phosphor for white light – Emitting diodes applications

Abstract

A novel green emitting Ba2CaZn2Si6O17:Eu2+ (BCZSO:Eu2+) phosphor was synthesized using conventional high temperature solid state reaction method. Powder X-ray diffraction was carried out to confirm the phase formation of the synthesized phosphors. Photoluminescence emission spectrum was recorded under excitation at 340 nm. The BCZSO:Eu2+ phosphor exhibited an intense asymmetric green emission band around 502 nm which originated from the 4f65d1 → 4f7 transition of Eu2+ ion. The optimum doping concentration of Eu2+ was found to be 0.06 mol. The energy transfer mechanism among Eu2+ in BCZSO phosphor was found to be a dipole–dipole interaction, and the critical distance (RC) for the Eu2+ ions calculated by the concentration quenching and spectral overlap methods were 23.2 Å and 13.7 Å, respectively. The decay curve of BCZSO:Eu2+ phosphors were discussed. The CIE chromaticity coordinate values (x = 0.259, y = 0.463) of BCZSO:Eu2+ phosphor were located in green region and the correlated color temperature was 7571 K. All these properties gave an indication that BCZSO:Eu2+ phosphor could be a potential green-emitting phosphor for UV based white light emitting diodes.