Investigation of luminescence properties and the energy transfer mechanism of Li 6 Lu(BO 3 ) 3 :Ce 3+ , Tb 3+ green-emitting phosphors

Li 6 Lu(BO 3 ) 3 :Ce 3+ , Tb 3+ phosphor was synthesized via a conventional solid-state method. The phase purity, photoluminescence properties, energy transfer mechanism, thermal stability and chromaticity coordinates were investigated. The absorption spectrum was comprised of broad bands in the UV region and the emission spectrum was consisted of characteristic peaks from both Ce 3+ and Tb 3+ under UV excitation. The amount of Ce 3+ was fixed to 3 mol% while Tb 3+ was varied from 20 to 80 mol% and the chromaticity coordinates were tuned from the blue to green region. The energy transfer mechanism between Ce 3+ and Tb 3+ was attributed to a quadrupole–quadrupole interaction and the critical distance was measured to be 8.12 Å. The overall performance of the phosphor was enhanced by the efficient energy transfer between Ce 3+ and Tb 3+ ions.