Electrical characterization of graphene structures in carbon oxide environment

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Thesis Type: Postgraduate

Institution Of The Thesis: Gazi Üniversitesi, Fen Bilimleri Enstitüsü, Turkey

Approval Date: 2013

Student: IRMAK KARADUMAN

Supervisor: SELİM ACAR

Open Archive Collection: AVESIS Open Access Collection

Abstract:

In this study, two different graphene samples were produced by Hummers method. First, the temperature-dependent electrical characterization of graphene samples was performed. Hall effect measurements taken under 0.4 T magnetic field by Van der Pauw technique were used from 30 to 300 K in steps of 10 K. The temperature-dependent resistivity of the samples, the carrier density and the Hall mobilities were analyzed. The resistivity was decreased with increasing temperature. Carrier concentration and mobility was found to be almost independent of the temperature. Samples were investigated with respect to susceptibility of carbon oxide gases (carbon monoxide and carbon dioxide). Graphene samples at different temperatures (300 K-320 K-350 K) and concentrations of gas (1000 ppm- 500 ppm- 250 ppm- 125 ppm- 50 ppm) related to time were electrically characterized. Samples were examined for sensitivity of carbon monoxide and carbon dioxide with different concentration. It was observed that Carbonmonoxide was increased the resistance of the samples, while carbondioxide was decreased.