Photoelectrical Properties of Composites from Organic Vacuum CVD-grown Multiwall Carbon Nanotubes and Conjugated Polymer

Composite of multiwall carbon nanotubes (MWNT) and conjugated polymers (CP) have been studied. MWNTs were prepared by the method of chemical vapor deposition (CVD) using metal phthalocyanine as starting material We have examined the transport and photophysical properties of the composit e film of poly(3-hexylthiophene)-MWNTs with different yolume fractions of MWNTs. Temperature dependence of the dark conductivity and the magnetoresistance of the porous MWNT mat and the nano-composite film have shown that the transport in MWNT/polymer composite is determined by two mechanisms: tunneling between tubes and bundles and semi-metallic conduction along the tubes. The enhancement of photoconductivity of composite films has been found near percolation threshold with maximum at ca. 3 vol.%. The enhanced photoresponse was observed due to the efficient charge separation and collection of photogenerated charge carriers in C₆₀-doped P3HT+MWNT composite film