SnO₂-Coated Silver Nanowire Networks as a Physical Model Describing Their Reversible Domain under Electrical Stress for Stable Transparent Electrode Applications

Thermal, electrical, and chemical instabilities affect the efficient integration of silver nanowire (AgNW) networks as transparent electrodes for energy and wearable electronics. By coupling experimental data and a simple physical model, we deduce the electrical areal power density ranges that AgNW networks can withstand, to observe either reversible modifications (i.e., electron–phonon interaction) or irreversible modifications (i.e., electrical sintering or degradation). This approach also allows us to predict the associated Joule heating temperature in the reversible domain for any applied voltage and initial resistance. It constitutes an efficient guide to design any device incorporating AgNW networks in which electrical current is applied. To improve AgNW stability, tin oxide (SnO2) coating has been deposited by atmospheric-pressure spatial atomic layer deposition at 200 °C. For a similar initial resistance, the observed maximum areal power density increases from 1.6 to 3.3 W cm–2 for bare AgNWs and 40 nm-SnO2/AgNW networks, respectively, and their associated Joule heating temperatures are 220 and 410 °C, respectively. In addition to the high electrical stability of SnO2/AgNW nanocomposites, we demonstrate their enhanced stability when exposed to either thermal stress up to 400 °C, or environmental stress with 80% of relative humidity at 70 °C for 2 weeks.