The outstanding performance (sheet resistance of 5 Ω sq–1 at transmittance of 90%) and strongly adhesive (30.7 J m–2) silver nanowires (AgNWs) are fabricated using flash-induced plasmonic welding (FPW) based on theoretical research of photothermal interactions. The FPW-processed AgNWs are utilized as electrodes of a transparent flexible energy harvester, and this device exhibits excellent transmittance and high electric output performance. The FPW methodology provides a high-tech solution for transparent flexible electronics.