SiC-based Piezoelectric Energy Harvester for Extreme Environment

This paper explores the feasibility of employing cubic silicon carbide on silicon wafer (3C-SiC-on-Si) as a vertical cantilever for the piezoelectric-based energy harvesting in the d31 mode intended for the extreme environments. 100nm thick 3C-SiC layer is plasma-etched out of the <100> silicon (Si) wafer and is employed as a bottom electrode, 1μm thick Aluminum nitride (AlN) as a piezoelectric thin film (active layer) and 50nm thick Molybdenum is sputtered on top of the cantilever structure as a top electrode. The length and width of the cantilever beam are 400μm and 30μm, respectively. The performances of the energy harvester using 3C-SiC and Si as bottom electrode and substrate are simulated and compared. The generated output voltage at 1KΩ load resistance is 7.85 times higher for the 3C-SiC based device. Additional tests at higher temperatures show 3C-SiC superior performances in terms of generated power and material strength