Enhanced solid-state luminescence and low-threshold lasing from starburst macromolecular materials

A novel series of nanosized monodispersed starburst macromolecular materials based on fluorene that exhibit desirable photo and electro-luminescence (EL) and lasing properties in dilute solution and solid-state was demonstrated. The photoluminescence (PL) spectra of macromolecules in thin-film format differ from those in dilute solution, supporting the absence of intermolecular interactions. The EL spectra data suggest that members of the macromolecular materials family are less prone to oxidation and to π-stacking. With simple 1D gratings comprising parallel 195 nm wide 100 nm deep etched stripes separated by 65 nm, a minimum lasing threshold is achieved at a lasing wavelength of 437 nm. The observed stability under electrical excitation in an OLED and the low threshold for optically pumped lasing is an attractive combination for progressing towards electrical injection lasers.