Up-Conversion Nanoparticles/PMMA Composites for Light-Emitting Applications

In this paper, we prepared KMnF3:Yb3+, Er3+ nanoparticles (NPs)/polymethyl methacrylate (PMMA) composites, NaYF4:Yb3+, Tm3+ NPs/PMMA composites and NaYF4Yb3+, Er3+ NPs/PMMA composites by in situ polymerization, and these NPs/PMMA composites can emit red, blue and green up-conversion fluorescence excited by 980 nm, respectively. The mixed white NPs/PMMA composites were obtained by adjusting the doping ratio of the above three NPs. These NPs/PMMA composites are transparent. We tested the up-conversion fluorescence spectra of all the NPs and NPs/PMMA composites, under 980 nm excitation. The up-conversion luminescence spectra of the NPs and NPs/PMMA composites are consistent, which further indicates that the in situ polymerization has not changed the chemical structure of the NPs. Then, we prepared transparent bulk polymers by curing these NPs/PMMA composites. Under 980 nm laser excitation, these NPs/PMMA bulk polymers can emit red, blue, green and white up-conversion emissions, respectively. The results indicate that the NPs/PMMA composites can be applied to three-dimensional (3D) display.