Improved zinc oxide film for gas sensor applications

Abstract

Zinc oxide (ZnO) is a versatile material for different commercial applications such as transparent electrodes, piezoelectric devices, varistors, SAW devices etc because of its high piezoelectric coupling, greater stability of its hexagonal phase and its pyroelectric property. In fact, ZnO is a potential material for gas sensor applications. Good quality ZnO films were deposited on glass and quartz substrates by a novel CVD technique using zinc acetate as the starting solution. X-ray diffraction confirmed the crystallinity of the zinc oxide film and SEM study revealed uniform deposition of fine grains. Undoped ZnO films were used for detection of dimethylamine (DMA) and H 2 at different temperatures by recording the change in resistivity of the film in presence of the test gases. The response was faster and the sensitivity was higher compared to the earlier reported ZnO based sensors developed in our laboratory. The main objective of this work was to study the selectivity of the ZnO film for a particular gas in presence of the others. The operating temperature was found to play a key role in the selectivity of such sensors.

Poly(vinylidene fluoride)/zinc oxide smart composite material

“…The piezoelectric ceramic material, ZnO, is extensively used due to its unique combination of electrical, optical, and piezoelectric properties. These applications include the following: liquid crystal displays and window coatings 9 , gas sensors covering various materials [10][11][12][13] , optoelectronic devices 14 , solar cells 15 , surface acoustic wave devices (SAW) 16 , and ultrasonic transducers 17 .…”

Doping of Polymers with ZnO Nanostructures for Optoelectronic and Sensor Applications

“…For metal oxides, one challenge is the low sensitivity at room temperature. They require higher operating temperatures and thus heating element has to be incorporated with the sensor (Roy & Basu, 2002) This increases the power consumption, which is not very appealing for handheld applications. Good selectivity is another challenge for metal oxide conductivity sensors.…”

Role of CuO-ZnO Heterojunctions in Gas Sensing Response of CuO-ZnO Thick Films

“…A wide range of gas sensors are developed using MOS (metal oxide semiconductors) because of their advantageous features like sensitivity to the air ambient conditions, low material cost, easy processing and simplicity in fabrication. The most commonly used MOS ZnO [1,2], SnO 2 [3], Fe 2 O 3 [4], In 2 O 3 [5], CeO 2 [6] in gas sensors are based on their change in electrical conductivity when they are exposed to test gases. At elevated temperatures (100-600 o C), these materials show large variations of electrical conductivity in response to the presence of traces of reactive gases in air.…”