FORMATION OF TTF-TCNQ CHARGE-TRANSFER COMPLEX IN COEVAPORATED FILMS

We have investigated the formation process of charge-transfer (CT) complex and the electric conductivity of TTF-TCNQ co-evaporated films by varying the growth temperature (T-g). The molar ratio of TTF to TCNQ in the co-evaporated film is constant at a value of 1.0 in the T-g range between 31 degrees C and 42 degrees C. The formation of the single crystal of the CT complex is enhanced and the electric conductivity increases with T-g. The temperature dependence of the surface conductivity is explained by the combination of the single-crystalline conduction of the grains and the activation-type conduction of the amorphous phase between the grains.