Improved thermal and electrical design for an all-Si thermoelectric micropower source

This work presents current achievements on the fabrication and characterization of an all-Si based planar thermoelectric microgenerator. Ordered dense arrays of Vapor-Liquid-Solid (VLS) grown p-type Si nanowires (Si NWs) are integrated in predefined thermally isolated microstructures as nanostructured thermoelectric active material. Optimizations in device processing and architecture that improved both thermal and electrical performances of the microgenerator resulted in a 70 fold increase in power output. Furthermore, the performance of microgenerators with Si NWs is compared to that of microgenerators with micron-sized Si beams as active material. Additionally, a 60 fold improvement in power output is observed by placing a cold-finger on top of the thermally isolated microstructure to demonstrate the effect of a heat exchanger, which is currently being implemented on the microgenerator.