Parameter Optimization of Semiconductor Gas Sensor under AC Impedance Measurement

Semiconductor gas sensors were confirmed to perform high linearity and a stable baseline under alternating current (AC) impedance measurements. However, a procedure to determine the optimal parameters of AC impedance measurements is still lacking. Taking the detection of SF₆ decomposition gas as an example, this work has established a model of semiconductor gas sensors under AC impedance measurement. Employing four types of sensors to detect three gases (H₂S, SO₂, and CO), the effectiveness of the optimization method has been validated, as well. With the high linearity and stable baseline obtained from AC impedance measurement, it enables rapid correction of temperature drift within environmental temperatures ranging from 10 to 30 °C. Overall, the proposed method can provide a novel approach to inhibit the drift failure of semiconductor gas sensors.