Fabrication of solution-processable, highly transparent and conductive electrodes via layer-by-layer assembly of functional silver nanowires

Highly transparent and conductive electrodes were prepared on glass substrates via layer-by-layer (LBL) deposition of functionalized silver nanowires (AgNWs). First, commercial nanowires were functionalized with cysteamine hydrochloride (CA) and 3-mercaptopropionic acid (MPA) to obtain positively and negatively charged AgNWs, respectively. Second, oppositely charged AgNWs were sequentially coated on a 3-aminopropyltriethoxysilane (APTES) modified glass substrate via LBL deposition, which provided highly controllable thin films in terms of optical transmittance and sheet resistance. Next, the multilayer film was subjected to thermal annealing to improve the electrical conductivity. Finally, AgNW multilayer film was characterized by UV-Vis spectrometer, field emission scanning electron microscope (FE-SEM), optical microscope (OM) and sheet resistance measurement by four-point probe method. The best result was achieved with 6-bilayer film providing a sheet resistance of 18.3 Ω/□ with an optical transmittance of 83.8% at 550 nm, which is comparable to commercial ITO electrode.