Plasmonic Hot-Carrier Engineering at Bimetallic Nanoparticle/Semiconductor Interfaces: A Computational Perspective

Plasmonic catalysis employs plasmonic metals such as Ag, Au, Cu, and Al, typically in combination with semiconductors, to drive diverse redox chemical reactions. These metals are good at harnessing sunlight, owing to their strong absorption cross-sections and tunable absorption peaks within the visible range of the solar spectrum. Unfortunately, facilitating plasmon-induced hot-carrier separation and subsequently harvesting them to improve catalytic efficiencies has been a problem at monometallic particle-semiconductor interfaces. To overcome this issue, this perspective focuses on recent computational methods and studies to discuss the advantages of designing bimetallic particles (core-shell or core-satellite), with a plasmonic-metal core and a less-plasmonic-metal shell on top, and coupling them with semiconductors. The aim of this approach is to favorably modify the interface between the plasmonic-metal particle and the semiconductor by introducing a thin section of a non-plasmonic metal in between. This approach is expected to enhance hot-carrier separation at the interface, preventing fast electron-hole recombination within the plasmonic-metal particle. Through a careful design of such bimetal/semiconductor configurations, by varying the size and composition of the non-plasmonic metal for example, and through appropriate utilization of quantum-mechanical modeling and experimental techniques, it is anticipated that plasmonic hot-carrier generation and separation processes can be studied and controlled in such systems, thereby enabling more-efficient plasmonic devices.