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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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Study of layers of Pd on InP
Černohorský, Ondřej ; Žďánský, Karel ; Proška, J.
Pd nanoparticles were prepared in colloid solution stabilized by AOT. The layers were prepared by electrophoretic deposition through the mask of polystyrene spheres. SEM measurement showed that particles in colloid solution are separated and after deposition they form small aggregates on InP. The size of these aggregates depends on the time of deposition. I-V characteristics were measured and then Schottky barrier height and ideality factor were calculated. The morphology of layers was monitored by SEM.
Fulltext: content.csg - PDF Plný tet: UFE 0374575 - PDF
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