Plasmon enhanced photocurrent in strongly coupled Ag@perylene core–shell nanowires

Abstract

Plasmon hot electron injection enhanced photocurrent has potential applications in light harvesting in photovoltaic devices. We demonstrate a cathodic photocurrent enhancement system utilizing strongly coupled Ag@perylene (Ag@Pe) core–shell nanowires, and the perylene shell thickness can be readily controlled. The strong coupling between the plasmonic resonance and molecular exciton resonance is evidenced by the substantial plasmon damping of Ag NWs and the enhancement of fluorescence of perylene with a red shift in Ag@Pe samples. The photocurrent of the Ag@Pe sample with a shell thickness of 5.8 nm (Ag@Pe-5.8 nm) shows a 16-fold enhancement compared to that of perylene. While, a simply mixed Ag–perylene sample displays only a 6-fold enhancement in photocurrent, indicating that the strong coupling in the Ag@Pe system plays a major role in the enhancement of photocurrent through hot electron transfer from the silver nanowires to perylene molecules. This strongly coupled Ag@Pe hetero-nanostructure could find potential applications in surface plasmon-driven, hot-electron solar cells and surface catalytic reactions.