Light emission from conjugated materials generated by charge carrier injection and photoluminescence

Soluble and stable poly(paraphenylene)-type ladder polymers with an extraordinary high degree of intrachain order and exceptionally low concentration of defects (in the electronic structure) belong to a class of best defined conjugated organic semiconductors currently available. The high intrachain order of our laddertype poly(paraphenylene) allows us to observe stimulated emission in the blue-green spectral region, which does not compete with dissipative processes. Parahexaphenyl, a highly stable oligomer of the poly(paraphenylene), can be produced in the form of single crystals, disordered thin films and highly ordered epitaxially grown thin films. We demonstrate the fabrication and the characterisation of highly efficient (up to 1000 cd/m2) red-green-blue (RGB) emission using an all organic colour conversion technique based on blue organic light emitting diodes.