Graphene has attracted research interest since its discovery in 2004 and professor Geim's receipt of the Nobel prize in 2010. It has been used for constructing a variety of electronics and sensors due to its unique electrical, mechanical, thermal, and optical properties.In this dissertation, we developed several technologies to control the electronic properties of graphene, which will pave the way for the future development of graphene nanoelectronics. First, since graphene properties vary depending on its number of layers, we identified a method for engineering the number of graphene layers using fine-tuned oxygen plasma etching. With this technique a single layer of graphene can be removed at a time. In addition, we demonstrated a template-less nanofabrication technique for batch production of graphene nanomeshes and multiribbons, and explored the feasibility of using these nanopatterns to construct field effect transistors (FETs). By introducing nanopatterns into pristine graphene, we could effectively open the band gap of graphene and convert it from semimetal into semiconductor. Furthermore, we studied a doping method for making n-type graphene with long-term chemical stability in air and stability at wide range of temperature. Highly stable n-type graphene with minimal defects was achieved using photo acid generator (PAG) mixed with SU-8 epoxy resin as an effective electron dopant and encapsulation. The electronic properties of the as-doped n-type graphene were confirmed by measuring its current transport characteristics and Fermi level shifts.Building on the aforementioned engineering techniques, we proposed a new Metal-SU8-graphene (MSG) technology, which is compatible with the conventional CMOS fabricationtechnology. MSG FETs were fabricated on both rigid and flexible substrates. A graphene invertor was also constructed as a proof of concept.Finally, we explored the potential applications of graphene in nanosensors, including chemical, temperature and flow sensors. We studied the possibility of using inter-layer graphene nano configuration to detect the absorption/desorption of different chemical molecules. Our results show a remarkable enhancement in graphene surface sensitivity, which can be attributed to extra edges and inter-sheet tunneling effects. We also demonstrated the capability of using graphene nanowires in temperature and flowrate sensing.
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