Photoluminescence in Eulytite-Type Structure Ca3Bi(PO4)3: Nd3+/Yb3+ Phosphors for Near-Infrared Applications

NIR emissions in Ca3Bi(PO4)(3) host are described. Nd3+was used as an activator for obtaining NIR emissions. Characteristic lines, with the most intense emission at 1064 nm (Nd3+: 4F(3/2) -> 4I(11/2)) were observed. The excitation was also through transitions within the Nd3+ f shell. The line at 584 nm was the most intense. The results on the activator concentration dependence of the luminescence intensity are also reported. The maximum intensity was detected for the composition Ca3Bi0.095Nd0.05 (PO4)(3). Concentration quenching was responsible for the decrease in the intensity after 5.0 mol%. From the concentration dependence studies, the critical distance for energy exchange between Nd3+ ions were calculated as 21.64 & Aring;. NIR emissions at the shorter wavelength of 983 nm could be achieved through the migration of energy from Nd3+ to Yb3+. Although Yb3+ does not luminesce by itself in this host, an intense emission was observed by virtue of this process. Synthesized phosphor has potential applications in optical devices for the NIR region.