Ultrathin Ag Film of Transparent Electrode for Flexible Schottky Photodetection and Enhanced Charge Transport

Abstract

Silver nanowire (AgNW)-based flexible devices with excellent transparency represent promising advancements for next-generation optoelectronic applications. Despite the inherently high conductivity of AgNW, open voids between nanowires often limit efficient charge collection, affecting overall device performance. This study addresses these limitations by introducing a highly conductive hybrid design comprising AgNW/Ag(O)/Al-doped ZnO (AZO). Compared with standalone AgNW, the addition of oxygen promotes the development of a continuous ultrathin Ag(O) layer (6 nm) inside the AgNW network’s macro-voids, resulting in 16 times greater mobility and improved thermal stability. This significant mobility improvement contributes to a 72% reduction in sheet resistance, a critical factor for optimizing device efficiency. Furthermore, Kelvin probe force microscopy (KPFM) analysis confirms the development of a Schottky junction at the Ag(O)/ZnO interface, which enhances charge generation, separation, and collection. This contributes to polyethylene terephthalate(PET)/ITO/ZnO/AgNW/Ag(O)/AZO-based photodetectors (PDs) achieving an impressive 21.5% increase in photocurrent efficiency compared to standalone AgNW-based PDs. The AZO layer also plays a crucial role by preserving the devices’ structural integrity and transparency, ensuring stable performance during prolonged operation and enabling the device to withstand various bending cycles. The device also demonstrates wide-band and wide-field-of-view photosensing─key for advanced cameras and antennas─reinforcing its role in next-generation optoelectronics.