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-transfer may take place. We present an experimenta l investigation of these processes in various binary polymer systems. These results are consistent with calculations of the relative energies of the i ntrachain and interchain excited states on pairs of different PPV-related c hains. In particular, we show experimentally and theoretically that charge transfer occurs at the interface between MEH-PPV and a cyano-substituted PP V derivative, whereas energy transfer occurs at the interface of PPV with t he same cyano-substituted polymer.