Exploiting Direct and Cascade Energy Transfer for Color-Tunable and White-Light Emission in Three-Component Self-Assembled Nanofibers

The co-self-assembly of a blue-light emitting organogelator and specifically designed green and red emitting hosts yields light-harvesting nanofibers with tunable emissive properties. In particular, under near-UV excitation white-light emission is achieved in organogels and their constituting nanofibers as demonstrated by confocal fluorescence microspectroscopy. Steady-state and time-resolved emission spectroscopies reveal that color tuning in three component nanofibers is achieved exploiting excitation energy transfers occurring between the blue-emitting anthracene derivative and the green- and red-emitting tetracenes, whereas the latter emission is further sensitized through a cascade blue-to-green-to-red transfer sequence. Moreover, excitation energy migrates through the blue-emitting components by exciton hopping before being transferred to the acceptors, thus contributing to the light-harvesting process.