Tri-system integration in metal-oxide nanocomposites via in-situ solution-processed method for ultrathin flexible transparent electrodes.

For stable operation of ultrathin flexible transparent electrodes (uFTEs), it is critical to implement effective risk management during concurrent multi-loading operation of electrical bias and mechanical folding cycles in high-humidity environments. Despite extensive efforts in preparing solution-processed uFTEs with cost-effective and high-throughput means, achieving in-situ nano-adhesion in heterogeneous metal-oxide nanocomposites remains challenging. In this work, we observed by serendipity liquid-like behaviour of transparent metal-oxide-semiconductor zinc oxide nanoparticles ( ZnO NPs) onto silver nanowires ( Ag NWs) developed by in-situ solution processed method (iSPM). This enabled us to address the long-standing issue of vulnerability in the nanocomposite caused by the interface of dissimilar materials between Ag NWs and ZnO NPs, resulting in a remarkably improved multi-loading operation. Importantly, substrate-integrated uFTEs constituted of the metal-oxide nanocomposite electrode semi-embedded in the polymer matrix of greatly thin <0.5 μm thickness is successfully demonstrated with the smooth surface topography, promoted by the tri-system integration including (i) Ag NW- Ag NW, (ii) ZnO NP- ZnO NP, and (iii) Ag NW- ZnO NP systems. Our finding unveils the complex interfacial dynamics associated with the heterogeneous interface system between Ag NWs and ZnO NPs and holds great promise in understanding the in-situ nano-adhesion process and increasing the design flexibility of next generation solution-processed uFTEs.