Two-dimensional Carbon Sheets Research Articles

Fabrication of Graphene Nanomesh by Using an Anodic Aluminum Oxide Membrane as a Template

Graphene, a one-atom-thick two-dimensional carbon sheet, has been extensively studied owing to its broad applications in nanoelectronics, [ 1 , 2 ] nanocomposites, [ 3 , 4 ] chemical sensors and biosensors, [ 5–10 ] solar cells, [ 11–13 ] and electrical and optical devices. [ 14–16 ] However, the application of graphene in fi eldeffect transistors (FETs) is limited because of its semi-metallic behavior with zero bandgap. [ 17 , 18 ] Cutting graphene sheets into nanoribbons led to bandgap opening, with current ON/OFF ratio large enough for transistor operation. [ 19–23 ] Unfortunately, FET devices based on the individual nanoribbons exhibited low driving current and conductance. [ 22 ]

Manipulating Thermal Conductance at Metal–Graphene Contacts via Chemical Functionalization

Graphene-based devices have garnered tremendous attention due to the unique physical properties arising from this purely two-dimensional carbon sheet leading to tremendous efficiency in the transport of thermal carriers (i.e., phonons). However, it is necessary for this two-dimensional material to be able to efficiently transport heat into the surrounding 3D device architecture in order to fully capitalize on its intrinsic transport capabilities. Therefore, the thermal boundary conductance at graphene interfaces is a critical parameter in the realization of graphene electronics and thermal solutions. In this work, we examine the role of chemical functionalization on the thermal boundary conductance across metal/graphene interfaces. Specifically, we metalize graphene that has been plasma functionalized and then measure the thermal boundary conductance at Al/graphene/SiO(2) contacts with time domain thermoreflectance. The addition of adsorbates to the graphene surfaces are shown to influence the cross plane thermal conductance; this behavior is attributed to changes in the bonding between the metal and the graphene, as both the phonon flux and the vibrational mismatch between the materials are each subject to the interfacial bond strength. These results demonstrate plasma-based functionalization of graphene surfaces is a viable approach to manipulate the thermal boundary conductance.

10310 欠陥を有するグラフェンの第一原理計算(計算機シミュレーションとその応用(2),OS.14 計算機シミュレーションとその応用)

Graphene is a two-dimensional carbon sheet in which the mobility of electrons is extraordinarily high. In this study, the stable structures, electron density distributions, and band structures of graphene sheets with Stone-Wales defects or stressed graphene sheets are calculated using first-principles calculations. The differences between the electronic characteristics of unstressed and stressed graphens are discussed.