The room temperature luminescence properties of Pr 3+ -doped gadolinium gallium garnet (GGG:Pr 3+ , Gd 3 Ga 5 O 12 :Pr 3+ ) nanocrystals (0.1, 1, 5 and 10 mol %) were evaluated. Increasing the Pr 3+ concentration in the nanocrystals resulted in a decrease of the 3 P 0 emission to lower lying states via the [ 3 P 0 , 3 H 4 ] f [ 3 H 6 , 1 D 2 ] cross-relaxation (CR) process. Similarly, a decrease in the 1 D 2 emission was observed and was attributed to the [ 1 D 2 , 3 H 4 ] f [ 1 G 4 , 3 F 3,4 ] cross-relaxation mechanism. The increase in cross-relaxation efficiency on increasing the Pr 3+ concentration was attributed to the smaller average interionic distances between the dopant ions. Dominant blue/green emission due to the 3 P 0 f 3 H 4 and 3 P 0 f 3 H 6 transitions was observed after laser excitation at 457.9 nm for Pr 3+ /Yb 3+ codoped nanocrystalline GGG samples. The blue/green emission decreased as the sensitizer (Yb 3+ ) concentration increased in the GGG samples. The observed near-infrared (NIR) 2 F 5/2 f 2 F 7/2 emission from the Yb 3+ ion, upon 457.9 nm excitation, suggests the presence of an energy transfer process from the Pr 3+ ions to neighboring Yb 3+ ions and results in a decrease of room temperature visible emission with increasing ytterbium concentration. Upconversion emission was observed for 0.1 and 1 mol % single doped samples. The nanocrystalline GGG:Pr 3+ ,Yb 3+ codoped samples showed a notable increase in upconversion emission intensity relative to the singly doped samples excited upon 980 nm excitation radiation. Upconversion was observed to occur via an ET process for the single and codoped samples.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.