Evaluation of the responses of a semiconductor gas sensor to gaseous mixtures under the application of temperature modulation

Abstract

A novel gas-sensing system based on a dynamic nonlinear response is reported to evaluate the effect of gaseous mixtures on the sensor response. A sinusoidal temperature perturbation was applied to a semiconductor gas sensor and the resulting conductance of the sensor was analyzed by fast Fourier transformation (FFT). The sensor response, which changed characteristically depending on the composition of the gaseous mixture, could be classified into three types (enhanced, suppressed, and preferential responses) by the mixture. To monitor the progress of the reaction of gases, the sample gas was analyzed by gas chromatography. The coexistent effect on the response to gaseous mixtures was theoretically simulated by considering the kinetics of gas molecules on the semiconductor surface.