Ultraflexible and High-Performance Multilayer Transparent Electrode Based on ZnO/Ag/CuSCN

Driven by huge demand for flexible optoelectronic devices, high-performance flexible transparent electrodes are continuously sought. In this work, a flexible multilayer transparent electrode with the structure of ZnO/Ag/CuSCN (ZAC) is engineered, featuring inorganic solution-processed cuprous thiocyanate (CuSCN) as a hole-transport antireflection coating. The ZAC electrode exhibits an average transmittance of 94% (discounting the substrate) in the visible range, a sheet resistance ( R_sh) of 9.7 Ω/sq, a high mechanical flexibility without R_sh variation after bending 10 000 times, a long-term stability of 400 days in ambient environment, and a scalable fabrication process. Moreover, spontaneously formed nanobulges are integrated into ZAC electrode, and light outcoupling is significantly improved. As a result, when applied into super yellow-based flexible organic light-emitting diode, the ZAC electrode provides a high-current efficiency of 23.4 cd/A and excellent device flexibility. These results suggest that multilayer thin films with ingenious material design and engineering can serve as a promising flexible transparent electrode for optoelectronic applications.