| Summary: | 碩士 === 國立中央大學 === 機械工程學系 === 106 === Graphene, a single graphite film with only one atomic layer thickness (0.34 nm), has excellent properties such as electron mobility (200,000 cm2V-1s-1), mechanical strength (1,100 GPa), the optical transmittance (> 97 %), chemical stability, high bending strength. It can not only be used in wearable devices but also be applied in photovoltaic panels to increase its stability. Thus, graphene has been considered as one of the promising materials to replace ITO (Indium Tin Oxide) in the future.
Chemical Vapor Deposition (CVD) is a mainstream method for growing graphene thin films on a transition metal substrate. By using this method, we can make large area and high uniformity graphene. However, the high cost limits its application for industrialization. In this experiment, we develop two methods, Roll to roll plasma-enhanced chemical vapor deposition (R2R-PECVD) and Batch to batch chemical vapor deposition (B2B-CVD) to reduce the cost to facilitate the industrialized production. In R2RCVD, different gas flow rate, temperature, plasma strength, and time have been considered to find the optimized condition for continuous growth. About B2B-CVD, to grow large-scale graphene in limited furnace tube. Rolling the copper foil and inserting quartz and carbon cloth, and aluminum oxide to prevent copper foil adhesion in high temperature.The quatz is used as scaffold. For carbon cloth and aluminum oxide, they were used as intercalation material. About PECVD, we couldn’t get continuous graphene because of the hydrogen etching effect. Although we can decrease the defect density from 8.77×1012 cm-2 to 3.33×1012 cm-2 by installing filter. The decreasing rate is approximate 60%, but graphene film is not continuous. By using B2B-CVD (carbon cloth as intercalation material), a large-area graphene with an area of 5×100 cm2 was obtained, damain size about 20 μm, sheet resistance only 750 Ω / sq, ID/IG radio 0.3, I2D/IG radio 0.9, defect density 2.43×1012 cm-2,and its charge carrier mobility ~1000 cm2V-1s-1.
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