Pd modified ZnO nanorod based high dynamic range Hydrogen sensor

Banerjee, N.; Roy, Shibendu Shekhar; Sarkar, Chandan Kumar; Bhattacharyya, P.

doi:10.1109/nano.2013.6720845

Cited by 7 publications

(3 citation statements)

References 15 publications

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“…Research efforts on gas sensing have been focusing on the improvement of sensing performance by improving their sensing characteristics such as the sensitivities, response and recovery times as well as detection limits of the sensors. For example, methods such as surface modification [ 11 , 16 ], catalyst doping [ 18 ], Schottky junction incorporation [ 19 , 20 ] and piezotronic integration [ 22 , 23 ] have been employed to achieve good sensing performance. However, the effects of operating bias voltages of sensors on the hydrogen sensing behaviours of the materials have rarely been investigated.…”

Section: Introductionmentioning

confidence: 99%

“…Applications of zinc oxide in hydrogen gas sensing have widely been studied over the past two decades, starting with the use of ZnO thin films with heating elements [7][8][9][10] incorporated to 1D nanostructures based on ZnO nanorods/nanowires as the sensing elements [11][12][13][14][15][16][17][18][19][20][21]. It has been reported that gas sensors based on 1D nanostructures are more superior in gas detection than thin film-based gas sensors because of their large surface-to-volume ratios of the former and also their dimensions are comparable to those of the gas analytes being analysed.…”

Section: Introductionmentioning

confidence: 99%

“…However, the effects of operating bias voltages of sensors on the hydrogen sensing behaviours of the materials have rarely been investigated. For example, multimeters were commonly used in determining the changes in resistance during sensing events [12,13,16,[24][25][26][27]. However, the multimeter is unable to perform both sourcing and measuring tasks simultaneously.…”

Section: Introductionmentioning

confidence: 99%

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Hydrogen sensing enhancement of zinc oxide nanorods via voltage biasing

2018

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The capability of zinc oxide (ZnO) as a hydrogen sensing element has been pushed to its limits. Different methods have been explored to extend its sensing capability. In this paper, we report a novel approach which significantly improves the hydrogen sensing capability of zinc oxide by applying a bias voltage to ZnO nanorods as the sensing elements. Zinc oxide in the form of aligned nanorods was first synthesized on an Au-coated Si(111) substrate using a facile method via the galvanic-assisted chemical process. The sensing performance of the zinc oxide nanorods was investigated in response to the applied biasing voltage. It was found that the sensitivity, response time and detection limit of the ZnO sensing elements were dramatically improved with increasing bias voltage. A 100% increment in sensing response was achieved for the detection of 2000 ppm hydrogen gas when the bias voltage was increased from −2 to −6 V with 70% reduction in response and recovery times. This remarkable sensing performance is attributed to the reaction of hydrogen with chemisorbed oxygen ions on the surface of the ZnO nanorods that served as the electron donors to increase the sensor conductance. Higher reverse bias voltages sweep the electrons faster across the electrodes. This shortened the response time and, at the same time, depleted the electrons in the sensor elements and weakens oxygen adsorption. The oxygen ions could then be readily removed by hydrogen, leading to a higher sensitivity of the sensors. This, therefore, envisages a way for high-speed hydrogen gas sensing with high detection sensitivities.

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