Optimizing thermoelectric transport through composite deposition of C-axis oriented interpolated multilayer bismuth films

Electron transport of low-dimensional materials is significantly influenced by both their orientation and grain size. Deposition energy can be used to tune grain size and orientation. Since the deposition energies of magnetron sputtering and thermal evaporation are different, multi-layer Bi films were prepared with different thicknesses of sputtering layer and evaporating layer. The c-axis oriented layer within a certain thickness can prevent the grain overgrowth along to the direction of film growth. This layer grown by thermal evaporation leads to the low-angle grain boundaries between grains. Carrier transport layer was introduced in this layer with low-angle grain boundaries. Importantly, it improves output power through increasing of ∆T.