Tuning the emission color of conjugated organic materials by photochemical reactions

In this contribution we investigate the energy transfer efficiency in blend films consisting of poly(fluorene) (PF) as host and a poly(para-phenylenevinylene) (PPV) derivative as guest materials. It is shown that the emission properties of the blend system can be efficiently tuned using a photoreaction with gaseous hydrazine. This is due to a photobleaching of the PPV type polymer, which results in a reduced energy transfer efficiency as a consequence of the breaking of π-conjugation. In contrast to oxidative bleaching the creation of non-radiative recombination centers is of minor importance.