Some of the most intriguing properties of graphene are predicted for specifically designed nanostructures such as nanoribbons. Functionalities far beyond those known from extended graphene systems include electronic band gap variations related to quantum confinement and edge effects, as well as localized spin-polarized edge states for specific edge geometries. The inability to produce graphene nanostructures with the needed precision, however, has so far hampered the verification of the predicted electronic properties. Here, we report on the electronic band gap and dispersion of the occupied electronic bands of atomically precise graphene nanoribbons fabricated via on-surface synthesis. Angle-resolved photoelectron spectroscopy and scanning tunneling spectroscopy data from armchair graphene nanoribbons of width N = 7 supported on Au(111) reveal a band gap of 2.3 eV, an effective mass of 0.21 m0 at the top of the valence band, and an energy-dependent charge carrier velocity reaching 8.2 × 105 m/s in the li...

Tight Binding Calculation of Molecules and Solids

Electronic Structure of Atomically Precise Graphene Nanoribbons

Graphite oxide was synthesized using various oxidation times and characterized by its physical and chemical properties. The degree of oxidation of the graphite oxide was systematically controlled via oxidation time up to 24h. Three phases of interlayer distances were identified by x-ray diffraction: pristine graphite (3.4A), intermediate (4A) and fully expanded graphite oxide (6A) phases. These phases were distinguished by an atomic ratio of O/C, which occurred from the different compositions of epoxide, carboxyl and hydroxyl groups. The band gap of the graphite oxides was also tuned via the oxidation time, resulting in direct band gap engineering from 1.7 to 2.4eV and strong correlation with the atomic ratio of O/C. (Some figures in this article are in colour only in the electronic version)

https://iopscience.iop.org/article/10.1088/0022-3727/42/6/065418/pdf

Tight Binding Calculation of Molecules and Solids

Citations

Electronic Structure of Atomically Precise Graphene Nanoribbons

Tailoring the characteristics of graphite oxides by different oxidation times

The Bloch Electron Response to Electric Fields: Application to Graphene

Related Papers (5)

Tight-Binding Model of Electronic States in a Liquid Metal

Environment-dependent tight-binding potential model

A tight-binding derivation of force constants : Application to covalent systems

Connection between energy relations of solids and molecules

A tight-binding molecular-dynamics study of the Si(001)H(1 × 1) surface