In this project, we developed methods to enhance the thermoelectric performance of silicon-based energy harvesters. We demonstrated how various nanofabrication methods reduce the thermal conductivity of thin films but preserve the electrical conductivity, thus increasing the overall efficiency.
Particularly, arrays of holes can reduce the material thermal conductivity several times. Alternatively, nanopillars of the surface can also reduce the thermal conductivity of underlying membrane. Finally, we proposed a cheap and simple method to reduce the thermal conductivity by covering the surface with an atomic layer of aluminum. Based on this method, we fabricated a planar thermoelectric devices shown in the figure above.
The project currently continues in Nomura lab.