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Characterization of Pd nanoparticle dispersed over porous silicon as a hydrogen sensor

Rahimi, F ; Sharif University of Technology | 2007

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  1. Type of Document: Article
  2. DOI: 10.1088/0022-3727/40/23/S03
  3. Publisher: 2007
  4. Abstract:
  5. Porous silicon samples were obtained by the electrochemical method and were impregnated with Pd by the electroless process. X-ray photoelectron spectroscopy illustrated that the surface of the samples is oxidized during the palladium deposition. Scanning electron microscopy showed how factors such as morphology and pre-oxidations of porous samples and the plating parameters including Pd-salt concentration, HCl concentration, temperature of the electroless solution and the time of process affect the growth and nucleation of Pd particles. Observations demonstrated that the illumination-assisted process on p-type samples has a drastic effect on the growth of palladium. Hydrogen sensing of these samples, which works on the basis of change in the Schottky barrier between the silicon and the palladium interface, was tested. Variations of the electrical resistance in the presence of diluted hydrogen at room temperature revealed that the best samples can sense hydrogen at levels down to several thousand ppm. This value is far below the flammability limit of hydrogen gas. In addition, the best samples have a very good selectivity to hydrogen. © 2007 IOP Publishing Ltd
  6. Keywords:
  7. Characterization ; Chemical sensors ; Deposition ; Impregnation ; Palladium ; Porous silicon ; Scanning electron microscopy ; X-ray photoelectron spectroscopy ; Electroless process ; Hydrogen sensors ; Schottky barrier ; Nanoparticles
  8. Source: Journal of Physics D: Applied Physics ; Volume 40, Issue 23 , 2007 , Pages 7201-7209 ; 00223727 (ISSN)
  9. URL: https://iopscience.iop.org/article/10.1088/0022-3727/40/23/S03