Comparing the performance of transparent, conductive ZnO/Ag/ZnO thin films that have an interlayer coating formed by either DC magnetron sputtering or HiPIMS

Abstract

Transparent electrodes (TEs) are essential components in many optoelectronic devices. Although indium tin oxide (ITO) has an excellent trade-off between optical transparency and electrical sheet resistance, it still suffers from several drawbacks, including the increasing cost of indium and poor long-term flexibility due to work hardening. This work presents the development of a new class of TEs based on ultrathin ZnO/Ag/ZnO samples in which Ag films with different film thickness are used as the metallic interlayer. XRD, XPS depth profiling, UV–vis-NIR spectrophotometer, Hall effect measurement, and a four-point probe system were used to characterize the properties of the fabricated films. Optimum thicknesses of Ag and ZnO top layer films were determined as those having high optical transmittance and good electrical conductivity. The main objective of this work has been to investigate how the density of the Ag interlayer in ZnO/Ag/ZnO film samples affects their optical and electrical properties. Silver layers prepared using DC magnetron sputtering (DCMS) have different densities to those prepared using high power impulse magnetron sputtering (HiPIMS). The optimum figure of merit at 3.53 × 10−3 Ω−1 was achieved for ZnO (0.6 nm)/Ag (9 nm)/ZnO (20 nm) multilayer films in which the Ag interlayer was fabricated using the HiPIMS method.