Indium-free flexible NiO/Ag NW composite transparent conductive thin films for transparent heater

The rapid oxidation and decomposition of the Ag nanowires (Ag NWs) in ambient conditions can lead to irreversible structural damage, largely overshadows their practical application in transparent conducting films. In this paper, we develop the highly transparent and low resistance composite thin films with a bilayer structure composed of NiO and Ag NWs. The transmittance and sheet resistance can be adjusted via controlling the density of nanowires. The NiO/Ag NW composites show a high figure of merit of 224 with the sheet resistance of 7.2 Ω/sq. and the average optical transmittance is about 80.3 % in the visible range. The mechanisms of improved transmittance and conductivity of NiO/Ag NW composites are proposed. Moreover, the resistance has no significant change after taping test, suggesting a strong adhesion of NiO/Ag NWs to the PET substrate. Furthermore, flexible NiO/Ag NW TCFs display an excellent stability to resist high temperature, high humidity and strong oxidation environment. Finally, transparent heater employing the flexible NiO/Ag NW TCFs as the electrode is obtained, showing a satisfactory heating behavior.