Altered Photothermoelectric Effects in Au nanowires via Surface Modification

Controlling morphology and composition via nanoscale structuring gives opportunities to improve the thermoelectric properties of materials for energy conversion and photodetection. In a previous study, we reported the open circuit photothermoelectric voltage in thin-film Au nanowire devices as a function of the position of an optical heat source. A focused laser beam is used to locally heat the metal nanostructure via a combination of direct absorption and excitation of plasmon resonance in Au nanowires. We found that the sign and magnitude of the net thermoelectric voltage is sensitive to structural defects, metal grain structure, and surface passivation of the nanowire. This finding opens the possibility of improved local control of the thermoelectric properties at the nanoscale. Here we report preliminary data on the alteration of the thermoelectric properties of Au nanowires via surface modification, including self-assembled monolayer formation