Novel Flexible Transparent Conductive Films with Enhanced Chemical and Electromechanical Sustainability: TiO₂ Nanosheet–Ag Nanowire Hybrid

Flexible transparent conductive films (TCFs) of TiO 2 nanosheet (TiO 2 NS) and silver nanowire (Ag NW) network hybrid were prepared through a simple and scalable solution-based process. The as-formed TiO 2 NS–Ag NW hybrid TCF shows a high optical transmittance (TT: 97% (90.2% including plastic substrate)) and low sheet resistance ( R s: 40 Ω/sq). In addition, the TiO 2 NS–Ag NW hybrid TCF exhibits a long-time chemical/aging and electromechanical stability. As for the chemical/aging stability, the hybrid TCF of Ag NW and TiO 2 NS reveals a retained initial conductivity (Δ R s / R s < 1%) under ambient oxidant gas over a month, superior to that of bare Ag NW (Δ R s / R s > 4000%) or RuO 2 NS–Ag NW hybrid (Δ R s / R s > 200%). As corroborated by the density functional theory simulation, the superb chemical stability of TiO 2 NS–Ag NW hybrid is attributable to the unique role of TiO 2 NS as a barrier, which prevents Ag NW’s chemical corrosion via the attenuated adsorption of sulfidation molecules (H 2 S) on TiO 2 NS. With respect to the electromechanical stability, in contrast to Ag NWs (Δ R / R 0 ∼ 152.9%), our hybrid TCF shows a limited increment of fractional resistivity (Δ R / R 0 ∼ 14.4%) after 200 000 cycles of the 1 R bending test (strain: 6.7%) owing to mechanically welded Ag NW networks by TiO 2 NS. Overall, our unique hybrid of TiO 2 NS and Ag NW exhibits excellent electrical/optical properties and reliable chemical/electromechanical stabilities.