Self-Limited Nanosoldering of Silver Nanowires for High-Performance Flexible Transparent Heaters

Silver nanowires (Ag NWs) are key materials to fabricate next-generation flexible transparent electrodes (FTEs). Currently, the applications of Ag NWs are impeded by the large wire-wire contact resistance. Herein, a self-limited nanosoldering method is proposed to reduce the contact resistance by epitaxially depositing silver nanosolders at the Ag NW junctions, which have a negligible effect on the optical transparency, while decreasing the sheet resistance of the Ag NW film from 18.6 to 7.7 Omega/sq at a transmittance of 90%. In addition, the deposited nanosolders at the junctions remarkably improve the electrical and mechanical stabilities of the Ag NW electrodes. Notably, this simple nanosoldering process can be rapidly conducted under room temperature and ambient conditions and is free of any technical support or specific equipment. This technique is easily applied to the nanosoldering of 210 x 297 mm FTEs. Based on these FTEs, a high-performance flexible transparent heater with a sheet resistance 3.7 Omega/sq at a transmittance of 82.5% is constructed. Because of the high heating rate (4.8 degrees C/s), the heater can produce uniform heating (145 degrees C) at a short response time (30 s) and low input voltage (6 V).