Boron oxynitride two-colour fluorescent dots and their incorporation in a hybrid organic-inorganic film

Bottom-up synthesis of fluorescent boron-nitride based dots is a challenging task because an accurate design of the structure-properties relationship is, in general, difficult to achieve. Incorporation of the dots into a solid-state matrix is also another important target to develop light-emitting devices. Two-colour fluorescent boron oxynitride nanodots have been obtained by a bottom-up synthesis route and incorporated into a hybrid organic-inorganic film. A combination of different analytical techniques such as XPS, XRD, TEM, UV–Vis, TGA-DTA and fluorescence has been used to characterise the structure, composition and properties of the boron oxynitride dots. The presence of defects in the boron oxynitride structure is the source of the two-colour fluorescence. The BN dots thermal stability is limited to around 100 °C; higher temperatures induce condensation of the structure, which leads to a lower emission. Upon incorporation into a hybrid organic-inorganic film deposited by spin-coating, the boron oxynitride dots maintain their fluorescence and have shown to be highly compatible with the sol-gel chemistry.