Effect of Synthesis Temperature, UV-Ozone Treatment, and Nanowire Diameter on the Failure of Silver Nanowire Electrodes

Silver nanowires (SNWs) have shown much promise as a lower cost flexible transparent electrode alternative to indium tin oxide. However, the stability of SNW electrodes has been brought into question. In this work, we studied the failure of SNW electrodes for different synthesis conditions and nanowire diameters with and without ultraviolet (UV)-ozone treatment. Transparent electrodes fabricated from nanowires synthesized at lower temperatures were found to have a lifetime of 53 days: the longest reported lifetime to the best of our knowledge for electrodes fabricated with nanowires less than 100 nm in diameter. In trials for transparent electrodes fabricated with SNW with average diameters of 80 nm, UV-ozone-treated films reached ultimate failure two days later than nontreated electrodes. This was attributed to the formation of silver oxide on the nanowires, which served as a protective layer and slowed the degradation process. Scanning electron microscope (SEM) images showed SNW electrodes made with an average nanowire diameter of 80 nm failed due to broken connections at the nanowire junctions. On the other hand, SNW electrodes made with an average diameter of 233 nm failed along the nanowires themselves, which suggests a different failure mechanism. The UV-ozone-treated larger diameter nanowire electrodes failed after 127 days, and the failure date of the nontreated SNW electrode remained undetermined after 153 days of continuous operation.