Electrical Properties of Chemically Derived Graphene

摘要: Graphene, an atomically thin sheet of carbon, is the most recent endeavor for application carbon nanostructures in conventional electronics. The envisioned creation devices completely carved out graphene could lead to revolution electronic circuitry. However, established technique obtain high quality sheets, i.e, by micromechanical cleavage cannot be easily upscaled, serving as impediment towards technological applications. present thesis dedicated study prepared via alternative scalable, yield and cost effective method which involves chemical reduction oxide. first part this describes detail atomic structure obtained method. Raman spectroscopy was used purpose followed Transmission Electron Microscopy (TEM) Near Edge X-Ray Fine Structure (NEXAFS) measurements locally probe these sheets with resolution. This revealed a highly disordered material, where regions perfect crystallinity are separated defect clusters. These defective patches were found contain remnant oxygenated functional groups. Electrical characterization chemically derived yielded ambipolar transfer characteristics similar that micromechanically cleaved graphene, albeit moderate performance. presence significant amount disorder precludes ballistic transport charge carriers traverse through predominantly thermally assisted variable range hopping combination field driven tunneling mechanism. clearly evidenced low temperature two-probe conduction performed on fabricated from sheets. Metal contacts play crucial role limiting applicability materials. Although performance based today sufficient variety applications, clear understanding engineering important utilization materials end In latter detailed presented; firstly grown CVD copper understand physics at simpler carbon-metal interface, photocurrent microscopy more complex interface between metal reduced oxide its implications device characteristics. A strong difference two kinds creating potential barrier owing them, whereas case synthesized version non invasive nature stable upto 300 °C. addition, Scanning Photocurrent investigation under gold, away contact edge provided interesting insights phenomena occuring gold thus highlighting importance adequate before successful transition into industry. Finally, novel vapor treatment employed enhance electrical Exposure ethylene 800 °C results improvement conductivities 2 orders magnitude lagging behind pristine graphene. structural increase conductivity occurred inspite considerable defects.