Sr2+ and Tb3+ doping tuning the size, morphology, and photoluminescence of NaCeF4 nanorods via solvothermal method

Abstract

Doping for nanocrystalline materials is of fundamental importance in tuning the size, phase, morphology and relational properties, such as fluorescence of rare earth fluoride nanocrystals. Here, we report hexagonal NaCeF4 nanorods with controlled size, morphology and photoluminescence were synthesized via solvothermal method by Sr2+ doping as well as Tb3+ doping. Transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) results illustrated Sr2+ which occupies Na+ site partially is crucial in controlling nanorods’ morphology, size, and emission intensity. The doping of Tb3+ as activation center can also play key role to tune the morphology of NaCeF4 nanorods containing Sr2+ from long nanobars to hexagonal prisms. Growth process revealed that ultrasmall SrF2 nanocrystals with cubic shape were fabricated firstly, and then Sr2+ doped NaCeF4 nanorods were obtained by oriented attachment and Ostwald ripening. The emission intensity was not only decided by Tb3+ doping concentration, but also morphology-dependent.