Temperature Dependence of Electrical Conductivity and Thermoelectric Power of Transparent SWCNT Films Obtained by Aerosol CVD Synthesis

The effect of pressing on temperature dependences of electrical conductivity σ(T) and thermoelectric power (Seebeck effect) S of single‐walled carbon nanotubes (SWCNTs) transparent films on polyester substrate has been studied. σ(T) has been described by the fluctuation‐induced tunneling model (FIT) conductance in the temperature range 20–298 K. At a temperature T < 20 K, three‐dimensional variable range hopping conductivity (VRHC) has been observed. Based on the estimation of current concentration n ≈1020 cm−3 from VRHC dependence, it has been found that metallic SWCNTs have made the main contribution to conductivity at T < 20 K. The value n obtained from S has been similar to the value obtained from VRHC estimation. The energy barrier between SWCNTs has been changed by pressing of films. Such pressing has led to increase in the electrical conductivity of the film by two orders of magnitude at room temperature. The measurement of conductivity in the process of synthesis has allowed us to control the repeatability of results and select samples with the necessary resistance values. Raman and optical spectroscopy, SEM and TEM have been used to determine the structural and geometric characteristics of the SWCNTs.