Excited-state energy- and charge-transfer at polymer/polymer interfaces

When an exciton diffuses to the interface between two conjugated polymers, either energy- or charge-transfermay take place. We present an experimental investigation of these processes in various binary polymer systems. These results are consistent with calculations of the relative energies of the intrachain and interchain excited states on pairs of different PPV-related chains. In particular, we show experimentally and theoretically that charge transfer occurs at the interface between MEH-PPV and a cyano-substituted PPV derivative, whereas energy transfer occurs at the interface of PPV with the same cyano-substituted polymer.