Direct Mapping of Reduced Resistivity and Electrical Noise Sources in Metallic Carbon Nanotube-Metal Hybrid Thin Films

We report a method for the nanoscale mapping of localized resistivity and noise source activities in metallic carbon nanotube (CNT)-metal hybrid thin films. In this work, a gold thin film was deposited on metallic CNT networks, and a current-noise map on the hybrid thin films was measured and analyzed, enabling the study of noise source activities in the films. The regions with CNTs embedded under the gold thin film showed the significantly reduced resistivity and noise source densities compared with pristine gold films, showing that not only conductivity but also noise characteristics of metallic electrodes can be improved by embedding CNTs in the hybrid film. Interestingly, we found distinctive correlations between the resistivity and noise source density on both CNT and gold film regions, implying that CNT-gold hybrid thin films have a conduction and noise characteristics like diffusive conductors. This method provides valuable insights about the charge transports in metallic CNT-metal hybrid films and can be utilized for various basic researches and practical applications using carbon nanotube-based devices.