Duan Research Group

Hetero-integrated Nanostructures and Nanodevices


Direct Room Temperature Welding and Chemical Protection of Silver Nanowire Thin Films for High-Performance Transparent Conductors

Yongjie Ge, Xidong Duan, Meng Zhang, Lin Mei, Jiawen Hu, Wei Hu, Xiangfeng Duan

J. Am. Chem. Soc. (2017)

Silver nanowire (Ag-NW) thin films have emerged as a promising next-generation transparent electrode. However, the current Ag-NW thin films are often plagued by high NW–NW contact resistance and poor long-term stability, which can be largely attributed to the ill-defined polyvinylpyrrolidone (PVP) surface ligands and nonideal Ag–PVP–Ag contact at NW–NW junctions. Herein, we report a room temperature direct welding and chemical protection strategy to greatly improve the conductivity and stability of the Ag-NW thin films. Specifically, we use a sodium borohydride (NaBH4) treatment process to thoroughly remove the PVP ligands and produce a clean Ag–Ag interface that allows direct welding of NW–NW junctions at room temperature, thus greatly improving the conductivity of the Ag-NW films, outperforming those obtained by thermal or plasmonic thermal treatment. We further show that, by decorating the as-formed Ag-NW thin film with a dense, hydrophobic dodecanethiol layer, the stability of the Ag-NW film can be greatly improved by 150-times compared with that of PVP-wrapped ones. Our studies demonstrate that a proper surface ligand design can effectively improve the conductivity and stability of Ag-NW thin films, marking an important step toward their applications in electronic and optoelectronic devices.
UCLA, Department of Chemistry and Biochemistry
607 Charles E. Young Drive East, Box 951569
Los Angeles, CA 90095-1569
E-mail: xduan@chem.ucla.edu