Response Analysis of Resistor-type Gas Sensor with Bias Voltage Condition

Many studies on the response analysis of resistor-type gas sensors have been reported. In this work, the bias dependent sensitivity of resistor-type gas sensors is investigated. The response to NO2 gas is 40% lower at high bias voltages than at low bias voltages. We analyze the effect of sensing material resistance and metal-semiconductor (sensing material) contact resistance on gas response. The measured results from the pattern to which the transmission line method was applied show that the bias-dependent response is observed only in the contact resistance component. This result is analyzed using the bias dependence of the Schottky barrier that occurs in the metal-semiconductor contact. The performance of the sensor can be improved by utilizing the bias dependent sensitivity characteristics.