Role of dimensionality and size in controlling the drag Seebeck coefficient of doped silicon nanostructures: A fundamental understanding

It is commonly believed that phonon drag, a phenomenon where electrons are dragged from the hot to the cold side of the sample by out-of-equilibrium phonons, does not play any significant role on the nanoscale. Here, the authors show that, even if the phonon-drag contribution is strongly reduced by nanostructuring, a silicon thin film of 100 nm thickness can still preserve more than 20% of the bulk phonon-drag contribution at 300 K along the in-plane direction of the thin film.