Giant piezoresistance in silicon-germanium alloys
Fahy, Stephen B.
American Physical Society
We use first-principles electronic structure methods to show that the piezoresistive strain gauge factor of single-crystalline bulk n-type silicon-germanium alloys at carefully controlled composition can reach values of G = 500, 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 G = 135 000, 13 times larger than that observed in Si whiskers. The improved piezoresistance is achieved by tuning the scattering of carriers between different (Delta and L) conduction band valleys by controlling the alloy composition and strain configuration.
Semiconductors , Temperatures
MURPHY-ARMANDO, F. & FAHY, S. 2012. Giant piezoresistance in silicon-germanium alloys. Physical Review B, 86, 035205.
©2012 American Physical Society