Tunable ultraviolet emission of ZnO quantum dots in transparent poly(methyl methacrylate)

We report experimental results on tuning ultraviolet (UV) emissions of colloidal ZnO quantum dots (QDs) with uniform size in poly(methyl methacrylate) (PMMA) through controlling their dispersion. Instead of using organic ligands, exfoliated nanoplatelets were utilized as an inorganic dispersant to achieve controlled aggregate sizes of ZnO QDs in PMMA. The polymer nanocomposites are highly transparent in the visible range and readily exhibit blueshifted UV luminescence as the aggregate size of ZnO QDs reduces. The mechanisms responsible for the observed dispersion-dependent UV emissions are also described. The above approach presents an alternative way to design inorganic/organic hybrids with desired physical properties.