Highly ordered plasmonic Au nano prism on conductive and transparent Indium Tin Oxide through nanosphere lithography*

The generation of localized surface plasmon (LSP), collective oscillation of conduction band electrons, at the surface of plasmonic nanostructures (PNs) by resonant light excitation has garnered broad scientific interest as it represents a promising way to manipulate light-matter interactions at the nanoscale, leading to various light harvesting applications.¹ The non-radiative decay of the LSP can result in the generation of hot carriers (holes and electrons) whose energy deviates from the equilibrium Fermi-Dirac distribution.² Hot carriers have been widely explored in several applications such as photodetection, quantum transport, photocatalysis, and solar energy harvesting.^3,4 It is therefore critical to develop and optimize strategies for the fabrication of highly ordered PN arrays on different types of surfaces. In this work, we used nanosphere lithography as a simple and high throughput technique to fabricate highly ordered Au nano prisms (AuNPs) on conductive indium tin oxide (ITO) film and insulating glass substrate. The fabricated nanostructures were characterized systematically using atomic force microscope (AFM) techniques. UV-vis extinction plot of the AuNPs on thin film exhibit LSPR peaks with maximum absorbance at 612 nm. The achieved result has experimental promises in understanding plasmon-driven chemical and physical processes, such as photocatalysis and hot carrier generation.