مبينا بوالحسني

Graphene, a two-dimensional structure of carbon atoms, has been widely used in the fabrication of volatile organic compounds (VOC) sensors due to its unique properties such as high surface-to-volume ratio, excellent conductivity, and ease of functionalization. These sensors play a vital role in air quality monitoring by absorbing VOC molecules and cause changes in the electrical properties of graphene. These changes are used as a signal to detect and measure VOCs. In this research, graphene-based sensors were made by photolithography, fluorinated with SF6 plasma and became semiconducting to detect ethanol gas. Optical scanning electron and atomic force microscopes were used to eva‎luate the quality and characterize fluorinated graphene while the degree of fluorination of was investigated by Raman spectroscopy, ATR and EDS. Finally, the sensing performance of ohmic and non ohmic samples was eva‎luated through current-voltage measurements while graphene was exposed to ethanol gas. The presence of fluorine makes graphene semiconducting while ethanol increase the number of charge carriers on graphene surface. These two approaches result in the sensing of ethanol. The results of this research demonstrate that the performance and accuracy of these sensors are highly dependent on key parameters including fluorination conditions (time, power and pressure), the effective area of fluorinated graphene, ohmic or non-ohmic junction with the substrate and applying gate voltage. Higher effective area increases the interaction with the analyte and ohmic or non-ohmic junction determines the electronic properties and stability of fluorinated graphene while sensing lowest concentrations of ethanol. These results are in agreement with sensing behaviuor in the literature and demonstrate non-ohmic potential in sensing ethanol with valueable perspective in research and industrial applications.

گرافن , گرافن فلوئوردار , حسگرهاي گازي مبتني بر گرافن , تركيبات آلي فرار , اتانول

Graphene , fluorinated graphene , graphene-based gas sensors , volatile organic compounds , ethanol

Bolhasani

Dr. Kazemi