SYNTHESIS AND STUDY ON THE PROPERTIES OF CAMOO4:EU3+ CO-DOPEDTB3+ MATERIALS TO ENHANCED RED PHOTOLUMINESCENCE

Ca0.99-yTb0.01MoO4:yEu3+nanophosphors weresuccessfullysynthesizedbyhydrothermal method. All the samples can be excited by 395nm wavelengths for generation of red color emission. Enhancement in 5D0â†Â'7F2 (616 nm) emission (f–f transition) of Eu3+ionis observed when Tb3+ionis co–doped in CaMoO4:Eu3+. This is due to the efficient energy transfer from Tb3+ to Eu3+ ions. Introduction of Tb3+ in the system does not lead to the change of emission wavelength of Eu3+. However, Tb3+and Eu3+co–doped in the system induces a shift in Mo-O charge transfer band absorption from 262nm to (413–431 nm). This may be due to the increase in electronegativity between Mo and O bond in the presence of Eu3+andTb3+leading to change in crystal field environment of Mo6+ in MoO42âˆÂ'. At the optimal concentration of Eu3+, an enhancement in emission by a factor of ∼5.6 in the respective excitation at 616nm (5D0â†Â'7F2) is observed. The chromaticity coordinates (CIE) of all Ca0.99-yTb0.01MoO4:yEu3+ nanophosphors are in the red region. The luminescence lifetime values are0.812 ms to 1.20 ms. The energy transfer is observed to occur mainly via dipole–dipole interactions.