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Influence of Thickness on Ethanol Sensing Characteristics of Doctor-bladed Thick Film from Flame-made ZnO Nanoparticles

View Article: PubMed Central

ABSTRACT

ZnO nanoparticles were produced by flame spray pyrolysis (FSP) using zinc naphthenate as a precursor dissolved in toluene/acetonitrile (80/20 vol%). The particle properties were analyzed by XRD, BET, and HR-TEM. The sensing films were produced by mixing the particles into an organic paste composed of terpineol and ethyl cellulose as a vehicle binder and were fabricated by doctor-blade technique with various thicknesses (5, 10, 15 μm). The morphology of the sensing films was analyzed by SEM and EDS analyses. The gas sensing characteristics to ethanol (25-250 ppm) were evaluated as a function of film thickness at 400°C in dry air. The relationship between thickness and ethanol sensing characteristics of ZnO thick film on Al2O3 substrate interdigitated with Au electrodes were investigated. The effects of film thickness, as well as the cracking phenomenon, though, many cracks were observed for thicker sensing films. Crack widths increased with increasing film thickness. The film thickness, cracking and ethanol concentration have significant effect on the sensing characteristics. The sensing characteristics with various thicknesses were compared, showing the tendency of the sensitivity to ethanol decreased with increasing film thickness and response time. The relationship between gas sensing properties and film thickness was discussed on the basis of diffusively and reactivity of the gases inside the oxide films. The thinnest sensing film (5 μm) showed the highest sensitivity and the fastest response time (within seconds).

No MeSH data available.


SEM micrographs of the selected areas showing the corresponding ZnO sensing layer (region 1) together with Au electrodes (region 2).EDS spectra for both regions emphasized clearly yield a signal corresponding to Zn, O, and Au were also shown in the inset.
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f10-sensors-07-00185: SEM micrographs of the selected areas showing the corresponding ZnO sensing layer (region 1) together with Au electrodes (region 2).EDS spectra for both regions emphasized clearly yield a signal corresponding to Zn, O, and Au were also shown in the inset.

Mentions: Fig. 10 (a) shows SEM images of sample S3. The image shows the selected regions of ZnO sensing layer (region 1) together with Au electrodes (region 2). Insets give the EDS elemental composition signal associated which each of regions as indicated. Region 1 and 2 emphasized clearly yield a signal corresponding to Zn, O, and Au. It can be clearly seen that the ZnO sensing layer doctor-bladed on the sensor substrate.


Influence of Thickness on Ethanol Sensing Characteristics of Doctor-bladed Thick Film from Flame-made ZnO Nanoparticles
SEM micrographs of the selected areas showing the corresponding ZnO sensing layer (region 1) together with Au electrodes (region 2).EDS spectra for both regions emphasized clearly yield a signal corresponding to Zn, O, and Au were also shown in the inset.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3756700&req=5

f10-sensors-07-00185: SEM micrographs of the selected areas showing the corresponding ZnO sensing layer (region 1) together with Au electrodes (region 2).EDS spectra for both regions emphasized clearly yield a signal corresponding to Zn, O, and Au were also shown in the inset.
Mentions: Fig. 10 (a) shows SEM images of sample S3. The image shows the selected regions of ZnO sensing layer (region 1) together with Au electrodes (region 2). Insets give the EDS elemental composition signal associated which each of regions as indicated. Region 1 and 2 emphasized clearly yield a signal corresponding to Zn, O, and Au. It can be clearly seen that the ZnO sensing layer doctor-bladed on the sensor substrate.

View Article: PubMed Central

ABSTRACT

ZnO nanoparticles were produced by flame spray pyrolysis (FSP) using zinc naphthenate as a precursor dissolved in toluene/acetonitrile (80/20 vol%). The particle properties were analyzed by XRD, BET, and HR-TEM. The sensing films were produced by mixing the particles into an organic paste composed of terpineol and ethyl cellulose as a vehicle binder and were fabricated by doctor-blade technique with various thicknesses (5, 10, 15 μm). The morphology of the sensing films was analyzed by SEM and EDS analyses. The gas sensing characteristics to ethanol (25-250 ppm) were evaluated as a function of film thickness at 400°C in dry air. The relationship between thickness and ethanol sensing characteristics of ZnO thick film on Al2O3 substrate interdigitated with Au electrodes were investigated. The effects of film thickness, as well as the cracking phenomenon, though, many cracks were observed for thicker sensing films. Crack widths increased with increasing film thickness. The film thickness, cracking and ethanol concentration have significant effect on the sensing characteristics. The sensing characteristics with various thicknesses were compared, showing the tendency of the sensitivity to ethanol decreased with increasing film thickness and response time. The relationship between gas sensing properties and film thickness was discussed on the basis of diffusively and reactivity of the gases inside the oxide films. The thinnest sensing film (5 μm) showed the highest sensitivity and the fastest response time (within seconds).

No MeSH data available.