Photothermal and Photoelectrical Energy Conversion in Plasmonic Nanostructures

Abstract

Surface plasmons, coherent oscillations of electrons in metals that can be excited with electromagnetic waves, are a key component in routing and manipulating light-matter interaction at nanometer length scales. Because of their deep-subwavelength mode volumes and strong field confinement, surface plasmons provide a means to realize numerous innovations such as metamaterials & metasurfaces, sub-diffraction limited imaging, sensing, and cloaking. While the non-radiative decay of plasmons has been long considered to be a parasitic loss, recent research has shown that it can be harnessed for a number of applications including photothermal heat generation, photodetection, photovoltaics and photocatalysis. Despite the significant advances, research in this area is still in its infancy with devices generally suffering from low efficiencies. This thesis focuses on understanding how plasmonic nanostructures can be properly engineered to take full advantage of the non-radiatively plasmon decay process for realizing new functionalities, as well as enhancing the efficiency of photothermal heating and photoelectrical energy conversion systems.