Building interconnects in carbon nanotube networks with metal halides for transparent electrodes

Achieving efficient and stable nanotube–nanotube interconnects is of great significance for translating the excellent electrical properties of individual carbon nanotubes (CNTs) to two-dimensional networks. In the present work, a modification technology to build interconnecting nodes in CNT networks with copper-halide crystallites is demonstrated. A pulse photonic curing system is utilized to realize a rapid heating and cooling process at a microsecond timescale. This process enables the manipulation of copper-halide crystallites, which not only results in the formation of nanotube–nanotube interconnecting nodes, but also improves halide p-type doping. As a result, the CNT–halide hybrid films exhibit sheet resistances of 55–65 and 90–110 Ω/sq at 85% and 90% optical transmittance (λ = 550 nm), respectively. The best dc-to-optical conductivity ratios reach 40. The sheet resistances are extremely stable without any degradation after 1000-h air exposure or 24-h heating at 400 °C, demonstrating their prospective potential for transparent electrodes.