Modification of conductivity of P3HT by addition of endometallo fullerene

Germanium endometallo fullerene was syn- thesized by arcing Ge-impregnated graphite rod as anode and pure graphite rod as cathode. Photoluminescence (PL) and resistance measurements suggest that there are effec- tive interactions at the interface of Ge endometallo fullerene and poly 3-hexyl thiophene (P3HT). Four-fold enhancement of conductance has been found by adding just one weight percentage of Ge endometallo fullerene in the P3HT matrix at room temperature. However, at lower and higher tem- peratures, the enhancement in conductivity is low com- pared with room temperature, indicating the efficient charge transfer across the interface at the temperature range of 300-350 K. Atomic force microscopy (AFM) images also confirm the fact that temperature makes the more ordered heterojunctions between P3HT and Ge endohedral metallo- fullerene, which, in turn, trigger charge separation across interfaces. A sharp quenching in PL intensity of P3HT at room temperature by adding Ge endometallo fullerene indicates a strong interaction between the two and this composite material can be useful in photovoltaic cell. V C 2009