Ultrathin Aluminum–Oxygen Interlayers Optimize Silver-Based Transparent Electrodes for High-Efficiency Photovoltaics

Transparent conductive films are critical bottlenecks in photovoltaic efficiency, with silver-based oxide/metal/oxide structures limited by high percolation thresholds that compromise optical performance. Here, we demonstrate that an ultrathin aluminum–oxygen seed layer dramatically enhances the ZnO/Ag/ZnO multilayer performance through oxygen-assisted deposition. Optimizing oxygen flow (12 sccm) and aluminum–oxygen thickness (1.5 nm) enables a remarkable 75% improvement in the figure of merit (72.8 × 10–3 Ω–1) while reducing silver thickness from 10 to 9 nm. First-principles calculations reveal that the aluminum–oxygen interlayer reduces the ZnO/Ag interfacial energy by promoting two-dimensional silver growth and suppressing island formation. Integration into silicon solar cells yields 5.73% power conversion efficiency after thermal treatment, representing a viable pathway to replace indium tin oxide in next-generation photovoltaics. This interface engineering strategy offers a scalable solution for high-performance, transparent electrodes across optoelectronic applications.