Percolation-engineered silver nanowire transparent electrodes for thermally robust operation

Silver nanowire (AgNW) transparent conductive films are enabling materials for flexible displays, touch panels, transparent photovoltaics, heaters, soft electronics, and sensors. Their reliability, however, is often limited not by average temperature rise but by highly localized Joule-heating hotspots at a small subset of current-carrying junctions. Here, we introduce a geometry-first, percolation-engineering strategy for designing dependable AgNW films. We explicitly model large-area (2.5 × 2.5 mm 2 ) networks across nanowire length and surface-coverage space, algorithmically separate the conducting backbone from non-percolating nanowires, and solve coupled electrical–thermal transport to map hotspot statistics. The average temperature rise scales quadratically with the applied current, Δ T ≈ S ET J 2 , where the electrothermal susceptibility coefficient S ET is governed primarily by network topology, including nanowire length, surface coverage, and junction resistance. This yields a practical design rule, J crit ( ℓ NW , ϕ NW ; Δ T crit ) = [Δ T crit / S ET ( ℓ NW , ϕ NW )] 1/2 , which directly converts morphology into the allowable operating current density for a chosen temperature-rise limit. Guided by these maps, we identify design regimes that suppress hotspots in optoelectronic electrodes while intentionally enhancing heating efficiency in transparent heaters. Experiments on 50 μm AgNW electrodes confirm the predicted electrothermal trends and support a junction-limited conductivity model with an effective conductivity ~20× lower at nanowire intersections. The resulting framework complements additive encapsulation and welding strategies and provides a practical route to select AgNW morphology for electrothermal robustness, while offering a natural basis for future integration with established AgNW optical-performance models.