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LAYERS OF METALS NANOPARTICLES ON VARIOUS SEMICONDUCTORS FOR HYDROGEN DETECTION
Černohorský, Ondřej ; Žďánský, Karel ; Yatskiv, Roman ; Grym, Jan
Metal nanoparticles have many interesting properties which is given by their space restriction. Their large active surface is very well exploited during catalysis. Pd and Pt are metals know for their ability to dissociate molecular hydrogen on single atoms. We prepared Schottky diodes on semiconductors InP, GaN, GaAs, and InGaAs to obtain hydrogen sensor. Method of preparation such diodes is electrophoretic deposition of Pd or Pt nanoparticles from their colloid solution onto semiconductor substrate. Over the layer of nanoparticles, porous metal contact was prepared. Hydrogen molecules are dissociated on these metal nanoparticles and single atom which settles on the interface between metal and semiconductor and they increase or decrease Schottky barrier height. By this method we can measure from 1 ppm H2 in the air, where the current change is over one order of magnitude
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Films of Metal Nanoparticles Deposited on Semiconductors by Electrophoresis: Technology and Characterization
Žďánský, Karel ; Zavadil, Jiří ; Kacerovský, Pavel ; Kostka, František ; Lorinčík, Jan ; Černohorský, O. ; Fojtík, A. ; Müller, M. ; Kostejn, M.
Layers of nanoparticles in micelle enclosures were deposited on InP substrates by electrophoresis from isooctane colloid solutions containing Pd or Ag nanoparticles. The layers were investigated by SIMS, low-temperature photoluminescence spectroscopy and topography, absorption spectroscopy, Raman spectroscopy and sensitivity to hydrogen. Photoluminescence of InP was enhanced by the layers of Pd or Ag nanoparticles. Schottky barriers made on the n-type InP with layers containing Pd nanoparticles showed significant sensitivity to hydrogen in contrast to those containing Ag nanoparticles.
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