Abstract
We use first-principles electronic structure methods to show that the piezoresistive strain gauge factor of single-crystalline bulk -type silicon-germanium alloys at carefully controlled composition can reach values of , three times larger than that of silicon, the most sensitive such material used in industry today. At cryogenic temperatures of 4 K we find gauge factors of , 13 times larger than that observed in Si whiskers. The improved piezoresistance is achieved by tuning the scattering of carriers between different ( and ) conduction band valleys by controlling the alloy composition and strain configuration.
- Received 26 March 2012
DOI:https://doi.org/10.1103/PhysRevB.86.035205
©2012 American Physical Society