Multi-Colour Electroluminescence of Dendronic AntennaeContaining Pyrenes as Light Harvesters

Dendronic antennae systems containing pyrene units as energy donors and a styrylpyridinium derivative as energy ac- ceptor show efficient energy transfer from the green-emitting pyrene excimer to the red-emitting acceptor. For the third den- dron generation the effective screening of the pyrene units on the acceptor provides thin films showing bright red emission. Single-layer light-emitting diodes prepared by properly balanc- ing the dendrons and donor units concentration in polyvinyl- carbazole show electroluminescence from the blue, green and red components of the monomeric donor, the donor excimer and the acceptor when excitons are generated in the polymer and subsequently transferred to the molecules by resonant energy transfer.