Microstructure and electrical conductivity of laminated Cu/CNT/Cu composites prepared by electrodeposition

Carbon nanotube (CNT) films were used as template for electrodeposition of Cu in different plating bath, and laminated Cu/CNT/Cu composites were prepared. The microstructure of all the laminated composites showed that Cu nucleus could insert into the pores of the CNT film, and formed an interfacial transition layer between the CNT film and the Cu coating. The electrodeposition behaviors of Cu on the CNT films in different plating baths were also analyzed. The results of electrical conductivity test showed that before annealing, the laminated composite prepared in basic acid plating bath has the highest electrical conductivity. After annealing at 900 °C for 2 h, the electrical conductivity of all specimens increased rapidly, and the electrical conductivity of the composite prepared in basic acid plating bath increased to 2.02 × 105 S cm−1. The annealing process was conductive to the diffusion and annihilation of voids within the interfacial transition layer, and the internal stress produced during the electroplating process could also be released through annealing. A simple and accurate quasi-classical model was proposed to calculate the resistance of the laminated composites. The measured resistances of the composites using four-point probe method were closer to that of the computed values, which indicated that the model used to describe the resistance of the laminated composite in the present study is feasible.