Graphene, even with excellent transport properties, still have serious drawbacks for practical applications. In particular, its gapless character makes it difficult to turn off the current in graphene transistors and leads to a poor saturation of current. Many efforts of bandgap engineering have been made to overcome these limitations. For instance, they consist in cutting 2D graphene sheets in...

Zigzag edges of graphene nanostructures host localized electronic states that are predicted to be spin-polarized. However, these edge states are highly susceptible to edge roughness and interaction with a supporting substrate, complicating the study of their intrinsic electronic and magnetic structure. Here, we focus on atomically precise graphene nanoribbons whose two short zigzag edges host e...

We discuss the electronic properties of graphene and graphene nanoribbons including ‘pseudo-Rashba’ spin–orbit coupling. After summarizing the bulk properties of massless and massive Dirac particles, we first analyze the scattering behavior close to an infinite mass and zigzag boundary. For low energies, we observe strong deviations from the usual spin-conserving behavior at high energies such ...

Abstract: In this study, using density functional theory and the SIESTA computationalcode, we investigate the electronic and optical properties of the armchair graphenenanoribbons and the armchair boron nitride nanoribbons of width 25 in the presence of atransverse external electric field. We have observed that in the absence of the electricfield, these structures are se...

When is an acene stable? The pronounced multiradical character of graphene nanoribbons of different size and shape was investigated with high-level multireference methods. Quantitative information based on the number of effectively unpaired electrons leads to specific estimates of the chemical stability of graphene nanostructures.

The emerging field of graphene brings together scientists and engineers as the discovered fundamental properties and effects encountered in this new material can be rapidly exploited for practical applications. There is potential for a two-dimensional graphene-based technology and recent works have already demonstrated the utility of graphene in building nanoelectromechanical systems, complex e...

Graphene has significant potential for application in electronics, but cannot be used for effective field-effect transistors operating at room temperature because it is a semimetal with a zero bandgap. Processing graphene sheets into nanoribbons with widths of less than 10 nm can open up a bandgap that is large enough for room-temperature transistor operation, but nanoribbon devices often have ...

We propose a graphene nanoribbon-based heterojunction, where a defect-free interface separates two zigzag graphene nanoribbons prepared in opposite antiferromagnetic spin configurations. This heterospin junction is found to allow the redirecting of low-energy electrons from one edge to the other. The basic scattering mechanisms and their relation to the system’s geometry are investigated throug...

Graphene and its quasi-one-dimensional counterpart, graphene nanoribbons, present an ideal platform for tweaking their unique electronic, magnetic and mechanical properties by various means for potential next-generation device applications. However, such tweaking requires knowledge of the electron-electron interactions that play a crucial role in these confined geometries. Here, we have investi...

Reduction of graphene oxide at the nanoscale is an attractive approach to graphene-based electronics. Here we use a platinum-coated atomic force microscope tip to locally catalyse the reduction of insulating graphene oxide in the presence of hydrogen. Nanoribbons with widths ranging from 20 to 80 nm and conductivities of >10(4) S m(-1) are successfully generated, and a field effect transistor i...