Controllable synthesis and down-conversion properties of flower-like NaY(MoO4 ) 2 microcrystals via polyvinylpyrrolidone-mediated

Abstract Double alkaline rare-earth molybdates NaY(MoO 4 ) 2 with multilayered flower-like architectures have been successfully synthesized via hydrothermal method in polyvinylpyrrolidone (PVP)-modified processes. The crystal structure and morphology of the obtained products were characterized by X-ray diffraction, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that reaction time and the amount of PVP have crucial influences on the morphology of the resulting novel microstructures. Under 450 nm excitation, Ho 3+ /Yb 3+ co-doped NaY(MoO 4 ) 2 samples exhibit 539 nm green emission and 960–1200 nm broadband near-infrared emission, corresponding to the characteristic lines of Ho 3+ and Yb 3+ , respectively. Moreover, increasing Yb 3+ doping enhances the energy transfer efficiency from Ho 3+ to Yb 3+ .