Sensing functions to NO and O2 of Nb2O5- or Ta2O5-loaded TiO2 and ZnO

Zinc oxide as an ozone sensor

“…For all films analyzed we have also noticed that, after exposing the films to an ozone atmosphere, ZЈ increases monotonically with the pressure of ozone used, recovering its initial impedance at a pressure of about 10 5 Pa. Figure 4 shows the dependence of −ZЉ on f, revealing a high noise contribution for the low frequency range. This behavior is attributed to the type of geometry used and the high resistance of the films.…”

“…7 The recent improvement of doped and undoped ZnO films prepared by various methods with the required gas sensitivity and selectivity of hydrocarbons, ammonia, oxygen, and NO x has contributed to the extensive study of this material as a gas sensor. [8][9][10] The authors of this work would like to emphasize the recent trend to develop gas sensors using thin film technology, since the gas sensing principle is associated to a surface phenomenon rather than to a bulk phenomenon. 11,12 To date, the use of oxide metal films as ozone sensors required an active heating element and subsequent operations at high temperatures (above 573 K), demanding a highenergy consumption for this type of sensor elements.…”

Electrical transport and Al doping efficiency in nanoscale ZnO films prepared by atomic layer deposition

“…ZnO is a transparent semiconductor with a wide and direct band gap of 3.4 eV. For this reason, ZnO-based thin films are widely studied (a) as semiconducting layers in thinfilm transistors, 1 (b) as active layers in gas sensors, [2][3][4][5][6] and (c) as alternatives to indium tin oxide, which is currently used as a transparent conducting oxide (TCO) [7][8][9][10] in solar cells. 11 For the latter application, ZnO thin films doped with B, 12 Al, [13][14][15] Ga, 16 etc., have been actively investigated, due to their high conductivity, optical transparency, high thermal stability, and last but not least the high material abundance.…”

Zinc Oxide Nanostructure Thick Films as H<sub>2</sub>S Gas Sensors at Room Temperature

“…Among these nanostructure-semiconducting materials, ZnO has been studied extensively for gas sensing application. It has been proved that ZnO is a good gas sensitive material for detection of both reducing and oxidizing gases [8][9][10][11][12][13][14][15][16]. Various gases have been tested for ZnO nanostructure sensor studied including ethanol, acetone, NO 2 , NH 3 , H 2 and CO 2 and hydrogen [17][18][19][20][21][22].…”