Structure and Electrical Properties of the Metallic Langmuir-Blodgett Film without Secondary Treatments

Takayoshi. Nakamura, G. Yunome, R. Azumi, Motoo. Tanaka, H. Tachibana, M. Matsumoto, S. Horiuchi, H. Yamochi, and G. Saito
[J. Phys. Chem., Vol.98, pp.1882-1887, 1994]

A metallic Langmuir-Blodgett (LB) film which does not require any secondary treatments obtained by using a charge-transfer complex of bis(ethylenedioxy)tetrathiafulvalene (BO) and decyltetracyanoquinodimethane (C₁₀TCNQ) was examined. A strong band in the IR region was observed due to the conduction electron. The average charges of the C₁₀TCNQ and BO in the LB film were -1 and +0.4, respectively, determined from the shift of the specific bands. The room-temperature conductivity of the film was 10 S/cm. The temperature dependence of conductivity of the film was well fitted by the formula sigma=AT-^a exp(-E_g/2k_BT), which is related to an activation-type conduction within the domain boundaries of a granular-structured film. The temperature dependence of the thermoelectric power clearly shows the metallic nature of the film. The thermoelectric power was positive and in the range of 15 muV/K at room temperature and tends to 0 muV/K at 0 K: the behavior of the temperature dependence of the thermoelectric power was determined by that of the metallic domains of partially-charge-transferred BO.