Study on TiO2-doped ZnO thick film gas sensors enhanced by UV light at room temperature

Purpose The purpose of this paper is to fabricate an ethanol sensor which has bio-friendly and eco-friendly properties compared to the commercially available ethanol sensors. Design/methodology/approach This paper describes the construction of a highly sensitive ethanol sensor with low ppm level detection at room temperature by integrating three techniques. The first deals with the formation of organic/inorganic p-n heterojunction. Second, tuning of structural parameters such as length, diameter and density of Zinc Oxide (ZnO) nanostructure was achieved through introduction of the Fe dopant into a pure ZnO seed layer. Furthermore, ultra-violet (UV) light photoactivation approach was used for enhancing the sensing performance of the fabricated sensors. Four different sensors were fabricated by combing the above approaches. The structural, morphological, optical and material compositions were characterized using different characterization techniques. Sensing behavior of the fabricated sensors toward ethanol was experimented at room temperature with and without UV illumination combined with stability studies. It was observed that all the fabricated sensors showed enhanced sensing performance for 10 ppm of ethanol. In specific, FNZ (Fe-doped ZnO seeded Ni-doped Zn nanorods) sensor exhibited a higher response at 2.2 and 13.5 s for 5 ppm and 100 ppm of ethanol with UV light illumination at room temperature, respectively. The photoactivated FNZ sensor showed quick response and speedy recovery at 18 and 30 s, respectively, for 100 ppm ethanol. Findings In this study, the authors have experimentally analyzed the effect of Fe (in ZnO seed layer and ZnO NRs) and Ni (in ZnO NRs) dopants in the room temperature sensing performance (with and without UV light) of the fabricated ethanol sensors. Important sensing parameters like sensitivity, recovery and response time of all the fabricated sensors are reported. Originality/value The Fe doped ZnO seeded Ni doped Zn nanorods (FNZ sample) showed a higher response at 2.2 s and 13.5 s for very low 5 ppm and 10 ppm of ethanol at room temperature under UV light illumination when compared to the other fabricated sensors in this paper. Similarly, this sensor also had quick response (18 s) and speedy recovery (30 s) for 100 ppm ethanol.

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Room-Temperature ZnO Nanoparticle Ethanol Gas Sensors under UV Illumination

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.486.39 ◽

2012 ◽

Vol 486 ◽

pp. 39-43 ◽

Cited By ~ 1

Author(s):

S.P. Chang

Keyword(s):

Gas Sensor ◽

Gas Sensors ◽

Spin Coating ◽

Room Temperature ◽

Uv Light ◽

Light Illumination ◽

Zno Nanoparticle ◽

Uv Illumination ◽

Potential Applications ◽

Nanoparticle Film

A zinc oxide (ZnO) nanoparticle gas sensor was formed by spin coating. We annealed the film at 400, 600, and 800°C for 1 h in air to create a gas sensor. The responses of the gas sensor to ethanol under UV light illumination were investigated. We found that the ZnO nanoparticle film annealed at 800°C had the highest sensitivity. This can be attributed to the fact that the defects of ZnO nanoparticle film annealed at 800°C are considerably more than those for the film annealed at other temperatures. This study demonstrates that ZnO nanoparticles have potential applications as room-temperature ethanol sensors.

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The Development of FeMn2O4 Gas Sensors at Room Temperature

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.605.211 ◽

2014 ◽

Vol 605 ◽

pp. 211-214 ◽

Cited By ~ 1

Author(s):

Ibrahim Gaidan

Keyword(s):

Thick Film ◽

Gas Sensors ◽

Room Temperature ◽

X Ray Diffraction ◽

Step Size ◽

X Ray ◽

Final Composition

Different ratios of MnO2/ Fe2O3, were used after being fired to form thick film gas sensors. The films were deposited on alumina substrates. The response of the sensors for a concentration range of 2500-5000 ppm increasing by a step size of 500 ppm of propanol at room temperature was investigated. The highest response was with the 75 / 25 MnO2/ Fe2O3sensor followed by the 25 / 75 and 50 / 50 MnO2/ Fe2O3sensors. The repeatability of the 75 / 25 mol. % MnO2/ Fe2O3to propanol at two concentration ranges 500-3000 and 2500 - 5000 ppm increasing with a step size of 500 ppm at room temperature was reported. The X-Ray Diffraction (XRD) is used to determine the final composition of the materials after firing. The XRD results show that MnO2reacts with Fe2O3to form FeMn2O4with Fe2O3and Fe3O4..

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