Browsing by Author "Cho, B.K."

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    Carbon 1s photoemission line analysis of C-based adsorbate on (111)In2O3 surface: The influence of reducing and oxidizing conditions [Articol]
    (Elsevier, 2016) Brînzari, Vladimir; Cho, B.K.; Korotcenkov, Ghenadii
    Synchrotron radiation photoemission study of C 1s line of (111) In2O3 surface was carried out under HV (high vacuum) doses of oxygen, carbon monoxide and water. Gas interaction with the surface was activated by heating of In2O3 monocrystalline film at temperatures of 160 or 250 °C. The study of complex structure of C 1 s line and evolution of its fine components allowed to establish their nature and to propose possible surface adsorbed species and reactions, including a direct chemisorption and dissociation of CO molecules. Reduction or oxidation of the surface determines whether the first (chemisorption) or the second (dissociation) process takes place. The latter is responsible for additional formation of ionosorbed oxygen. Both processes have not been previously reported for In2O3 and for conductive metal oxides.
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    In2O3- and SnO2-based ozone sensors: Design and characterization [Articol]
    (Taylor & Francis Ltd, 2018) Korotcenkov, Ghenadii; Brinzari, Vladimir; Cho, B.K.
    This article describes in detail the SnO2 and In2O3 metal oxides as materials for designing solid state conductometric ozone sensors. The main focus of this article is on the description of the SnO2 and In2O3 films' structural parameters important for gas sensor design and on the establishment of the main regularities of the film parameters influence on the sensor characteristics. Advantages and disadvantages of approaches used for optimization of ozone sensor parameters are also analyzed. In particular, surface modification, bulk doping of SnO2 and In2O3, and the use of 1D structures and hybrid materials are considered. The main factors, controlling parameters of SnO2- and In2O3-based ozone sensors, are determined, and recommendations for the process of the SnO2 and In2O3 films deposition, facilitating the search of the film parameters and the fabrication technologies that optimize the ozone sensor performance, are formulated.