Nanostructured gold thermocouple for photodetection*

The Seebeck coefficient of a metal depends on the energy-dependent electrical conductivity, which in turn depends on the energy-dependent electron mean free path and the material band structure. At the nanoscale, when the geometric size is comparable with the mean free path of the electrons, single metal thermocouples can be fabricated by changing the material geometry across the thermocouple. By using plasmonically-resonant structures, different device geometries and sizes can be used for wavelength sensitive light detection. We will present experimental data and simulations of single metal gold nanostructures with different geometries that are plasmonically active with IR laser illumination. We will discuss how these devices can be used for photodetection and discuss future applications for these measurements.