Distinguishing Among Gases with a Semiconductor Sensor Depending on the Frequency Modulation of a Cyclic Temperature

Abstract

A gas-sensing system based on a dynamic nonlinear response shows enhanced selectivity of the sensor response toward sample vapors. A cyclic temperature composed of fundamental and 1.5-th harmonics was applied to a SnO 2 semiconductor gas sensor and the resulting conductance of the sensor was evaluated by a polynomial approximation. The dynamic nonlinear responses to the samples were further characterized by the addition of 1.5-th harmonic perturbation as a frequency modulation. These characteristic sensor responses under frequency modulation were considered theoretically based on a reaction-diffusion model for the semiconductor surface.

Application of Temperature Modulation-SDP on MOS Gas Sensors: Capturing Soil Gaseous Profile for Discrimination of Soil under Different Nutrient Addition

“…Temperature modulation has successfully enhanced the selectivity of (thick/thin) SnO 2 in distinguishing a single or multicomponent by applying certain modulation or analysis for optimum result as reported in [4][5][6], even on catalytic gas sensor [7]. Moreover, it also succeeded on the TGSs [8][9][10][11]. In the early investigation of this technique, pulse/thermalcycling technique was used which mostly was applied on TGSs as reported by Lee and Reedy [1].…”