Modeling, Simulation, Fabrication, and Characterization of a 10- $\mu$ W/cm 2 Class Si-Nanowire Thermoelectric Generator for IoT Applications

We propose a planar device architecture compatible with the CMOS process technology as the optimal current benchmark of a Si-nanowire (NW) thermoelectric (TE) power generator. The proposed device is driven by a temperature gradient that is formed in the proximity of a perpendicular heat flow to the substrate. Therefore, unlike the conventional TE generators, the planar short Si-NWs need not be suspended on a cavity structure. Under an externally applied temperature difference of 5 K, the recorded TE power density is observed to be $12~\mu \text{W}$ /cm 2 by shortening the Si-NWs length and suppressing the parasitic thermal resistance of the Si substrate. The demonstration paves a pathway to develop cost-effective autonomous internet-of-things applications that utilize the environmental and body heats.