Temperature Coefficient of Gauge Factor

Dopant Control

Changes in temperature alter the mobility and distribution of charge carriers within the semiconductor energy bands, which directly affects the piezoresistive response. In silicon sensors, the gauge factor generally decreases as the temperature rises because the carriers gain thermal energy and become less sensitive to lattice deformation. The rate of this decrease is highly dependent on the dopant type and concentration within the piezoresistive region.

High doping levels reduce this thermal dependency but also reduce the overall sensitivity of the sensor.

Sensor Calibration

Characterizing this coefficient requires measuring the sensor output at multiple controlled temperatures while applying a known mechanical strain. These calibration measurements generate compensation curves that are programmed into the sensor’s signal-conditioning electronics. By applying these digital corrections, the sensor can output accurate strain values despite changes in the ambient temperature.

Operational Boundary

At extremely high temperatures, the intrinsic carrier concentration exceeds the dopant concentration, which causes the piezoresistive effect to drop rapidly. This thermal limit restricts the reliable operating range of the sensor to temperatures below this transition point.