Highly flexible, stable and transparent capacitors with enhanced performances by composite electrodes of AZO and metallic nanomeshes

Abstract

Transparent and flexible capacitors with composite electrodes consisting of ZnO:Al(AZO) and Cr–Au nanomeshes and dielectric ZrO2 films were directly prepared on plastic substrates. The transparent composite electrodes exhibited an ultralow sheet resistance (5.6 Ω·square−1) and good flexural properties. ZrO2 thin films were grown by atomic layer deposition to serve as dielectric layers. The capacitors showed a higher capacitance density (17.8 fF μm−2) than that capacitors with AZO electrodes (9.8 fF μm−2) while maintained an extra-low leakage current density (1.3 × 10−9 A cm−2 at 1 V). Additionally, the quality factor was increased from 9.6 to 80.5 at a frequency of 1 MHz with the incorporation of Cr–Au nanomeshes, which greatly reduced the power consumptions. More importantly, the capacitors with the composite electrodes exhibited excellent bendability, good cycling stability, and relatively high transparency. It is, therefore, a promising route for application in developing transparent, flexible, high-performance and low-cost integrated circuits.