Study of piezoresistance in GexSi1−x whiskers for sensor application

The piezoresistance of GexSi1−x (x=0.01-0.05) solid solution whiskers with impurity concentrations in the vicinity to metal-insulator transition at the temperature range 4.2-300 K was studied. A 'giant' piezoresistance was found at low temperatures (T<50 K) in the samples. The absolute magnitude of the gauge factor depends on the doping level and for the whiskers with ρ300K=0.018Ωcm it is around 3.4×104 at the temperature 4.2 K. The observed effect was used for design of high sensitive strain sensors.