Effective passivation of Ag nanowire network by transparent tetrahedral amorphous carbon film for flexible and transparent thin film heaters.

We developed effective passivation method of flexible Ag nanowire (NW) network electrodes using transparent tetrahedral amorphous carbon (ta-C) film prepared by filtered cathode vacuum arc (FCVA) coating. Even at room temperature process of FCVA, the ta-C passivation layer effectively protect Ag NW network electrode and improved the ambient stability of Ag NW network without change of sheet resistance of Ag NW network. In addition, ta-C coated Ag NW electrode showed identical critical inner and outer bending radius to bare Ag NW due to the thin thickness of ta-C passivation layer. The time-temperature profiles demonstrate that the performance of the transparent and flexible thin film heater (TFH) with the ta-C/Ag NW network is better than that of a TFH with Ag NW electrodes due to thermal stability of FCVA grown ta-C layer. In addition, the transparent and flexible TFHs with ta-C/Ag NW showed robustness against external force due to its high hardness and wear resistance. This indicates that the FCVA coated ta-C is promising passivation and protective layer for chemically weak Ag NW network electrodes against sulfur in ambient.