Morphology determination of functional poly[2-methoxy-5-(3,7-dimethyloctyloxy)-1,4-pheny[enevinylene]/poly[oxa-1,4-phenylene-1,2-(1-cyanovinylene)-2-methoxy,5-(3,7-dimethyloctyloxy)-1,4-phenylene]1,2-(2-cyanovinylene)-1,4-phenylene] blends as used for all-polymer solar cells

Poly[2-metlioxy-5-(3,7-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) blended with poly[oxa-1,4phenylene-1,2-(1-cyanoinylene)-2-methoxy,5-(3,7-dimethyl- octyloxy)-1,4-phenylene-1,2-(2-cyanovinylene)-1,4-phenylene] (PCNEPV) has been used as the active layer for an all-polymer photovoltaic cell. The photovoltaic performance of devices is improved by a thermal treatment, which alters the morphology of the active layer. The morphology of the MDMO-PPV/ PCNEPV blend has been studied with conventional transmission electron microscopy and energy-filtered transmission electron microscopy based on electron energy loss spectroscopy. The nitrogen of the cyano group within the PCNEPV has been be detected, and two-dimensional nitrogen distribution maps have been acquired. Nitrogen-rich domains have a size of approximately 20-50 nm and are homogeneously distributed over the entire film. (c) 2005 Wiley Periodicals, Inc.