Details

Autor(en) / Beteiligte

• Gaiardo, A.
• Fabbri, B.
• Giberti, A.
• Guidi, V.
• Bellutti, P.
• Malagù, C.
• Valt, M.
• Pepponi, G.
• Gherardi, S.
• Zonta, G.
• Martucci, A.
• Sturaro, M.
• Landini, N.

Titel

ZnO and Au/ZnO thin films: Room-temperature chemoresistive properties for gas sensing applications

Ist Teil von

• Sensors and actuators. B, Chemical, 2016-12, Vol.237, p.1085-1094

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2016

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• •The sensing properties of pure ZnO and Au decorated Zno thin films were deeply investigated at room temperature, in photo-activation mode.•ZnO gold clusters decorated layers showed better chemoresistive properties than the pure ZnO ones.•ZnO decorated with gold nanoclusters showed an attractive behaviour with NO2 as the incident radiation had energy lower than that of ZnO bandgap. Zinc Oxide has been widely investigated for its photocatalytic properties, which enhance the bulk/surface charge transfer at room temperature. At the same time, the doping of semiconductor materials with metals allows the modification of their physical and chemical properties, and hence their performance as gas sensors. The aim of this work was to investigate the difference between thin-film sensors based on pure ZnO nanoparticles and on gold-cluster decorated ZnO in photo-activation mode. The nanopowders were synthesized through simple sol-gel methods and chemically, morphologically and structurally characterized. Thin films were deposited by spin coating onto alumina substrates. The sensing layers were tested with several gases in photo-activation mode, illuminated with radiation wavelengths of 525, 468, 400 and 385nm. Gold-decorated ZnO thin film showed some interesting features, such as better chemoresistive properties than pure ZnO under photo-activation mode, when illuminated with a wavelength of 385nm. A selective response of the sensing film to NO2 under green light irradiation was observed, in particular in dry air condition. Furthermore, the humidity effect on the sensing responses was investigated, highlighting a possible application of Au/ZnO for the detection of few ppm of SO2 with a high percentage of relative humidity.