ABSTRACT
We report what we believe to be the first use of organic nanostructures for efficient colour conversion of gallium nitride light emitting diodes (LEDs). The particular nanomaterials, based on star-shaped truxene oligofluorenes, offer an attractive alternative to inorganic colloidal quantum dots in the search for novel and functional 'nanophosphors'. The truxenes have been formed into a composite with photoresist and ink-jet printed onto microstructured gallium nitride LEDs, resulting in a demonstrator hybrid microdisplay technology with pixel size approximately 32 microm. The output power density of the hybrid device was measured to be approximately 8.4 mW/cm(2) per pixel at driving current density of 870.8A/cm(2) and the efficiency of colour conversion at drive current of 7 mA was estimated to be approximately 50%.
ABSTRACT
Crystallization of 2,4,5,7-tetranitro-9-(dicyanomethylene)fluorene [DTeF; systematic name: 2-(2,4,5,7-tetranitrofluorene-9-ylidene)propanedinitrile] and 2,4,5,7-tetranitrofluoren-9-one (TeNF) from chlorobenzene in the presence of pi-donor compounds yielded the chlorobenzene solvate, C(16)H(4)N(6)O(8) x C(6)H(5)Cl, and the bis(chlorobenzene) solvate, C(13)H(4)N(4)O(9) x 2C(6)H(5)Cl, respectively. Both structures comprise mixed stacks of twisted fluorene moieties interspersed with nearly parallel chlorobenzene molecules. Solvent-free crystals of DTeF and TeNF were obtained from pure chlorobenzene.
