On the fundamental mechanism of multicolor light generation from Y2O3:Dy3+/Eu3+ nanocrystal

Nanomaterials possess attractive properties which their bulk counterparts do not have. Generation of different colors of light by changing size and/or composition of nanomaterials are well established. Further, there are plethora of reports on dissemination of different properties from an individual nanomaterial. However, fundamental mechanisms leading to multicolor light generation from a nanocrystalline sample are seldom reported. In this work, three different colors of light are tuned from a single sample of Y2O3:Dy3+/Eu3+ nanocrystal. Its fundamental mechanism is proposed on the basis of Forster resonance energy transfers. Photoluminescence energy transfer mechanisms leading to the different colors are also elucidated. Our work opens up research on fundamental mechanisms for a class of materials which can generate multicolors of light from a single sample. This multicolour light generating nanocrystal has potential in the field of multicolor display, security printing, sensor, etc.