One-Pot Synthesis and Purification of Ultralong Silver Nanowires for Flexible Transparent Conductive Electrodes

Metal nanowires (NWs) have become the most promising candidates for the next generation of flexible transparent conductive electrodes (FTCEs), with high transmittance and low sheet resistance. In this work, ultralong silver NWs (Ag NWs), ∼220 μm (even larger than 400 μm) in length and ∼55 nm in diameter (aspect ratio: ∼4000), were synthesized via a one-pot polyol process using high molecular weight poly(vinylpyrrolidone) (M_w = 1 300 000) and an appropriate concentration of FeCl₃ (12.5 μM) through hydrothermal reaction. The prepared Ag NWs were purified by a filter cloth (pore size: about 30 × 50 μm²) to remove the Ag nanoparticles and short-length Ag NWs. The FTCE based on the ultralong Ag NWs without any post-treatments exhibits low sheet resistance of 155.0 Ω sq^-1 and transmittance of 97.70% at 550 nm. The outstanding performance of FTECs demonstrated that the ultralong Ag NWs are ideal materials for applications in flexible transparent optical devices.