Detecting high-concentration gases is challenging by metal oxide semiconductor (MOX) gas sensors, because the voltage signal would become saturated. In order to solve this problem, the zooming p + n field-effect transistors (FETs) circuit has been designed, combining an n-type enhancement-mode FET (EMFET) and a p-type depletion-mode FET (DMFET). Th...
Detecting high-concentration gases is challenging by metal oxide semiconductor (MOX) gas sensors, because the voltage signal would become saturated. In order to solve this problem, the zooming p + n field-effect transistors (FETs) circuit has been designed, combining an n-type enhancement-mode FET (EMFET) and a p-type depletion-mode FET (DMFET). Th...
Published in Journal of Sol-Gel Science and Technology
Iron and cobalt doped zinc oxide were prepared by the sol–gel method. The doping concentration was varied between 5 and 10 wt.%. Structural and morphological features of the samples were investigated comparatively by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). They...
Published in Sensors & Actuators: B. Chemical
We report, for the first time, discriminating among complex odors using a single generic tin oxide gas sensor. The sensor heater is biased with high magnitude voltage impulses of predetermined thermal impacts adjusted to produce step-like pallet temperature rises of different magnitudes. The sensor pallet is exposed to aromas collected from various...
Published in Semiconductors and Semimetals
This chapter provides an overview of the working principle of n- and p-type metal oxide gas sensors. Moreover, it gives an insight into the state of the art operando approaches and why it is necessary to combine several techniques to get as much information about the sensing process as possible. The last part covers the different doping types and h...
The performance of a gas pre-concentrator/gas chromatographic column/gas sensor system was studied step by step towards benzene vapor in presence of 1,3 butadiene vapor. The pre-concentrator, based on an activated carbon of high adsorption capacity, was first characterized using a GC/FID system. By this way, the adsorption capacity of each pollutan...
In this paper, the use of a new technique to obtain transient sensor information is introduced and its usefulness to improve the selectivity of metal oxide gas sensors is discussed. The method is based on modulating the flow of the carrier gas that brings the species to be measured into the sensor chamber. In such a way, the analytes’ concentration...
