Optical and electronic properties of thin PDAs films with very narrow excitonic bandwidth

Soluble polycarbazolyldiacetylene systems (PCDAs) having long alkyl chains on the carbazolyl substituents have been recently prepared. In these systems, PCDAs chains in the solid state are assembled in hexagonal columnar structures. Thin films of these PCDAs show a very high value for the third order susceptibility. In order to study the effect of the substituents in the electronic properties of PCDAs we have inserted -CO(CH 2 ) n CH 3 groups on the carbazolyl rings, thus decreasing the electron-donor effect of carbazole. Non-birefringent thin films of excellent optical quality are obtained whose optical and electronic properties are here reported.