doi:10.1038/nindia.2017.41 Published online 27 March 2017
By using rare-earth elements, researchers have synthesized light-emitting nanorods for use in display devices, security ink and biomedical devices1.
Rare-earth compounds exhibit intense and sharp emission properties, unlike commonly used organic dyes, metal oxides and semiconducting quantum dots. The optical, electrical and magnetic properties of rare-earth compounds can also be easily tuned.
To tap into their potential, materials scientists from CSIR-National Physical Laboratory, New Delhi prepared bundles of one-dimensional nanorods by using yttrium oxide, ytterbium and holmium.
These rods, with a diameter of 100 nm, possess photoluminescence, a phenomenon in which light is absorbed and then emitted. The nanorods displayed strong green emission.
Sophisticated imaging techniques reveal that even a minor variation (0.1%) in photoluminescence intensity can be easily observed in the nanorods, making them potentially useful for display devices.
The applications of luminescent materials also depend on how long photoluminescence lasts. Photoluminescence in the range of milliseconds to microseconds have several potential applications such as optical display devices, bio-medical and security ink applications.
The results show that photoluminescence of nanorod bundles are highly useful for making advanced optical display devices and security ink.
“Besides providing a better way to understand the properties of luminescent nanomaterials, this study offers a new technique to fabricate highly uniform display devices,” says lead researcher, Bipin Kumar Gupta.
1. Kumar, P. et al. Experimental observation of spatially resolved photoluminescence intensity distribution in dual mode upconverting nanorod bundles. Sci. Rep.7, 42515 (2017)