Charge- and energy-transfer processes at polymer/polymer interfaces: A joint experimental and theoretical study

When an exciton approaches the interface between two conjugated polymers, either energy or charge transfer can take place. We present a detailed experimental investigation of these processes in various binary polymer systems. The results are interpreted in the context of quantum-chemical calculations that provide estimates of the relative energies of intrachain versus interchain excited states in pairs of various PPV-related chains. In particular, we show that charge-transfer occurs at the interface between MEH-PPV and a cyano-substituted PPV derivative, whereas energy transfer takes place at the interface of PPV with the same cyano-substituted polymer.