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Optoelectrical characterization of well oriented n-type zno nanorod arrays on p-type GaN templates
Yatskiv, Roman ; Grym, Jan ; Schenk, Antonín ; Vaniš, Jan ; Roesel, David ; Chlupová, Šárka
A heterojunction formed between a single n-type ZnO nanorod and p-type GaN template was successfully prepared by low cost chemical bath deposition technique. Periodic circular patterns were fabricated by focused ion beam etching through poly(methyl methacrylate) mask to control the size, position, and periodicity of the ZnO nanorods. A possible growth mechanism is introduced to explain the growth process of the nanorods. Optical and electrical properties of the heterojunctions were investigated by low temperature photoluminescence spectroscopy and by the measurement of current-voltage (I-V) characteristics. The I-V characteristics were measured by directly contacting single ZnO nanorods with the conductive atomic force microscopy tip. The diode-like rectifying behavior was observed with a turn-on voltage of 2.3 V and the reverse breakdown voltage was 5 V
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Study of deposition of catalytic materials into fuel channels of micro-fuel cells on a chip
Chlupová, Šárka ; Matolínová, Iva (advisor) ; Grym, Jan (referee)
This diploma thesis is interested in usage of Electron Beam lithography process as an instrument of transport of contacts and catalytic layers to micro-channels of the micro monolithic planar fuel cell. Experimental part includes optimization of the PMMA resist deposition method on the 3D topography - spray coating - is performed with alternative spray coating system. The optimal spin speed resist, molecular weight and concentration is chosen during the optimization. Parameters of the exposition, developing and lift-off are also modified and three EBL processes are performed. The first ensures deposition of Au contacts to the channels; the second is for application of Pt layer to the cathode channel and the last aimed to cover the anode channel with CeO/CNx layer. All layers are deposited by magnetron sputtering.
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Contacting nanostructures for sensor measurements
Chlupová, Šárka ; Matolínová, Iva (advisor) ; Dvořák, Filip (referee)
Title: Contacting nanostructures for sensor measurements Author: Šárka Chlupová Department: Department of Surface and Plasma Science Supervisor: Doc. Mgr. Iva Matolínová, Dr., Department of Surface and Plasma Science Abstract: The bachelor thesis is dealing with contacting nanostructures using electron beam lithography (EBL). Work was carried out in a scanning electron microscope on a mica dielectric substrate with WOx nanorods on the surface in order to prepare a sensor for the detection of H2. In this experiment, parameters for individual sub- processes of EBL were modified. Optimal thicknesses of the PMMA resist 120K (5% anisole) and PMMA 996K (1% anisole) were selected to prepare multilayer resist for an EBL mask. On the resulting bilayer resist electron beam exposure doses were optimized. The appropriate dose was selected and used for creating a matrix designed to contact the WOx nanorods supported on mica. To contact the nanostructures, macrocontacts were deposited on the surface of mica at first, and then the EBL process ran. The result was a conductive connection of the tungsten oxide nanorods by created nanocontacts with macrocontacts. Sensoric properties of the sensor in this way contacted were subsequently successfully tested with H2. Keywords: Sensor, WOx nanorods, Electron beam lithografhy
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