| Summary: | 碩士 === 國立高雄應用科技大學 === 電子工程系 === 106 === Graphene is a zero-bandgap two-dimensional material with a single layer of carbon atoms. Its excellent physical properties have promising potential to various applications. Graphene makes scientists the new understanding of two-dimensional materials. Compared to other preparation methods, high-quality and large-area graphene can be prepared by chemical vapor deposition (CVD). In this study, Taguchi method with several process parameters, such as process temperature, gas flow rate, and growth time, was used to optimize the graphene preparation. The optimized graphene has I2D/IG > 2, FWHM of 30, and mobility of 1780 cm2/Vs. Grain boundaries and surface defects of copper foil substrates strongly influence the graphene preparation. In this study, lots of pre-treatment procedures, such as acid etching, electrolytic polishing, and thermal annealing, were also performed to improve the status of copper foil substrate. Carrier mobility of graphene prepared with optimized pre-treatment procedures was increased to 1907 cm2/Vs. However, the process temperature of graphene preparation is higher than 1000 ˚C, which is too high to be integrated with other electronic device. Therefore, a transfer process is needed to graphene-based device fabrication. The transfer process was also improved in this study and thus the carrier mobility of graphene was increased to 2157 cm2/Vs. The optical properties, flexibility, and thermal stability of graphene were also investigated. In addition, a simple graphene/silicon heterojunction was fabricated for Schottky diode application.
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