How can sensitive and selective semiconductor gas sensors be made?

A Semiconductor Gas Sensor Based on Nonlinearity: Utilization of the Effect of Competition on the Sensor Responses to Gaseous Mixtures

“…We have also demonstrated that the effect of competition on the sensor response provides useful nonlinear information for the analysis of gaseous mixtures, i.e., both quantitative and qualitative analysis of a sample gas are possible based on the dynamic nonlinear response upon mixing with another gas. The effects of competition on the sensor responses to gaseous mixtures should be clarified by further investigation, e.g., consideration of the reaction between sample gases on the sensor surface and the semiconductor barrier height depending on the status of the adsorbed gas and the Debye length [29,39] in the present model. Thus, consideration of the effect of competition on the sensor response based on the nonlinearity may be significant for chemical analysis in the food, environmental, and clinical fields, as a type of nondestructive analysis.…”

CdO-TiO2 nanocomposite thin films for resistive hydrogen sensing

“…At higher temperature, the carrier concentration increases and the Debye length (L D ) decreases. The Debye length (L D ) is given by following equation [28].…”

Catalytic properties of oxide nanoparticles applied in gas sensors

“…The use of nanoparticles assures a high accessible surface for the gas molecules, allowing the use of very small amounts of substance in the sensitive layer and thus the miniaturizing of the devices. In 2 O 3 is explored as a sensor material based on the resistivity changes to different gases by several authors [1][2][3][4][5][6]. In this work we are communicating a series of results obtained using indium oxide-based catalytic layers doped with Au, as capacitive-type devices for measuring gases such as hydrogen, carbon monoxide, hydrocarbons, nitrogen oxides, ammonia and mixtures thereof, in oxygen-containing atmosphere.…”