Improving the Thermal Stability and Oxidation Resistance of Silver Nanowire Films via 2-Mercaptobenzimidazole Modification

For electronic devices, a tradeoff exists between the structural stability and electrical conductivity of silver nanowires (Ag NWs). Self-assembled monolayers (SAMs) containing sulfur functional groups formed on the Ag nanowire surface through Ag–S covalent bonds can act as a passivation layer, thereby improving the corrosion resistance. This work explored the effect of 2-mercaptobenzimidazole (MBI) SAM on the thermal and oxidation resistance of Ag NW films. The conductivity, surface morphology, chemical properties, and thermal stability of MBI-modified Ag NW films were analyzed via four-point probe measurements, field-emission scanning electron microscopy, x-ray photoelectron spectroscopy (XPS), and thermal characterization. In particular, the results show that the MBI layer can significantly reduce the oxidation of Ag NW films at room temperature for 60 days. Moreover, the MBI layer improved the thermal stability of the Ag NW films up to 230°C by inhibiting Ag diffusion. The unmodified Ag NW film completely lost conductivity after heating and oxidation treatment. In contrast, the sheet resistance of the Ag NW film modified by 0.1 wt.% MBI only increased from 65 Ω/\(\square\) to 106 Ω/\(\square\), and 156 Ω/\(\square\) after heating treatment and oxidation test, respectively.