An Oxide‐Dispersed Preparation Strategy for Silver Ultrathin Films with Low Percolation Threshold Thickness, Subnanometer Smoothness, and Prominent Durability

Abstract

AbstractIn this work, an oxide‐dispersed strategy is developed for Ag ultrathin films with low percolation thickness, ultrasmoothness, and excellent stability, which are all critical for their practical applications. Through simply sputtering of CdO‐containing Ag target, nearly amorphous Ag ultrathin films with CdO dispersion are prepared on glass or polyimide substrates under room temperature. The CdO‐dispersed Ag thin films exhibit a low percolation threshold of 5 nm with a transmittance of 89% at 550 nm and a sheet resistance of 32.9 Ω sq−1. The Ag–CdO films also feature an ultrasmooth growth with roughness remaining at 0.2 nm for further deposition. Furthermore, the CdO‐dispersed Ag thin films remain stable under 250 °C annealing in air, and highly accelerated stress test at 121 °C, 97% relative humidity (RH), and 0.1 MPa for 36 h. Flexible heaters with indium‐tin‐oxide (ITO)/CdO‐dispersed Ag/ITO/polyimide structure can reach a working temperature of 450 °C within a few seconds. In addition, the oxide‐dispersed strategy for preparing Ag ultrathin films with low percolation, subnanometer smoothness, and prominent durability is further verified using SnO2 and ZnO. The present study provides new insights for the growth and properties of ultrathin metallic films, and pushes forward the practical applications of ultrathin metallic films in optoelectronic devices.