Luminescence, energy transfer, colour modulation and up-conversion mechanisms of Yb, Tm and Ho co-doped YMoO.

A series of novel up-conversion luminescent Yb/Ln (Tm, Ho, Tm/Ho)-doped YMoO (YMO) nanocrystals were synthesized using the sol-gel method. The consistent spherical morphology of the nanocrystals with different doping ratios was found to be profiting from the homogenisation and rapid agglomeration of the composition in the gel state and calcining process. The X-ray diffraction (XRD) and field-emission scanning electron microscope images were employed to confirm perfect crystallinity and uniform morphology.