A conformal silver wire top electrode for enhanced hydrovoltaic power generation from silicon nanowire arrays

Abstract Silicon nanowire (SiNW) arrays present a promising platform for high-performance hydrovoltaic devices (HDs). However, charge extraction from the SiNW tips remains a key challenge. This work introduces a silver wire (AgW) network as a conjoint top electrode to enable high-efficiency charge collection. The in-situ assembled AgWs form a conformal conductive network that bridges numerous SiNW tips in parrel, effectively interconnecting independent SiNW hydrovoltaic microunits and facilitating efficient charge transport to grid electrodes. Systematic optimization reveals that an AgW areal density of 0.050 mg cm ⁻² leads to a significant performance boost of SiNW HDs, achieving a 101% increase in output power density compared to reference devices. Furthermore, the AgW conjoint top electrode exhibits good stability under hydrodynamic flushing (13.5 m min ⁻¹ ), with only an initial 12% performance decay due to the removal of loosely bound nanowires, followed by consistent output over repeated flushing cycles. This work demonstrates a simple yet effective strategy for enhancing charge collection in SiNW HDs, offering a practical pathway toward new-type silicon-based energy harvesting systems.