Supramolecular light-emitting polymers for solution-processed optoelectronic devices

Supramolecular light-emitting polymers (SLEPs) based on host-guest interactions were developed for solution processed organic electronic devices. The dibenzo-24-crown-8 functionalized blue-emitting conjugated oligomer 1 and green-emitting conjugated oligomer 3 were used as the host materials, and the dibenzylammonium salt functionalized blue-emitting conjugated oligomer 2 was used as the guest material. The resulting linear SLEPs were obtained from the self-organization of the host and guest oligomers, which were confirmed by the nuclear magnetic resonance, viscosity and differential scanning calorimetry studies. Highly fluorescent SLEP nanofibers can be easily obtained by drawing or electron-spinning from the equimolar solution of the host and guest oligomers. The photophysical and electroluminescence properties of the resulting SLEPs were fully investigated. It was found that the SLEPs' emission colors can be well tuned from blue to green with significantly enhanced photoluminescent efficiencies by using 3 as the dopant, which is due to the efficient energy transfer caused by the exciton trapping on narrow band gap host oligomer 3 in the SLEPs. As a result, the designed SLEPs showed comparable electroluminescence device performances to those analogous traditional conjugated polymers. Considering the precisely defined starting monomers and catalyst-free polymerization process for the designed SLEPs, combining the good device performances, the present study provides a promising alternative route to develop solution processed semiconductors for optoelectronic applications.