Thermoelectric devices are commonly composed of a bismuth-tellurium compound which is expensive and have limited resource. Alternatively, silicon, a semiconductor may be a prominent material in thermoelectric devices. However, high thermal conductivity in bulk Si affects the thermo-electric efficiency. On the contrary, the nanostructured Si i.e. nanowires can be used in enhancing thermoelectric properties.
Researchers from Process Tomography Research Group & Instrumentation (PROTOM-i), the research arm of UTM Faculty of Electrical Engineering in their research, investigate the performance of Silicon Nanowire Arrays (SiNWAs) and bulk Si material as thermoelectric power.
SiNWAs as an element in power harvesters utilize green technology in which there are solid-state parts that are able to increase the longevity of a power harvesting device, while its non-toxic, emissions-free and noiseless characteristics encourage a healthier environment. Inexpensive and commonly found silicon material, and a simple fabrication technique without any requirement of expensive tools to build SiNWAs power harvesting device promote economic advantages to the manufacturers and end-consumers.
a) Fabricated device with copper sheets attached (left); and close-up FESEM image of SiNWAs (right). b) The thermal image at each layers of the device (i.e. top Cu sheet, Si and bottom Cu sheet)