Controlling Electronic Structure and Transport Properties of Zigzag Graphene Nanoribbons by Edge Functionalization with Fluorine

Abstract

In this work, we report a detailed study of the electronic structure and transport properties of mono- and difluorinated edges of zigzag graphene nanoribbons (ZGNR) using density functional theory (DFT). The calculated formation energies at 0 K indicate that the stability of the nanoribbons increases with the increase in the concentration of difluorinated edge C atoms along with an interesting variation of the energy gaps between 0.0 to 0.66 eV depending on the concentration. This gives a possibility of tuning the band gaps by controlling the concentration of F for terminating the edges of the nanoribbons. The DFT results have been reproduced by density functional tight binding method. Using the nonequilibrium Green functional method, we have calculated the transmission coefficients of several mono- and difluorinated ZGNR as a function of unit cell size and degree of homogeneous disorder caused by the random placement of mono and difluorinated C atoms at the edges.

2D Material Enabled Offset‐Patterning with Atomic Resolution

“…Using this approach, we can produce inhomogeneously functionalized graphene as evidenced by an increase in contrast around intrinsic bilayer areas ( Figure 1b) which differs from previous reports. [17,22] To identify the origin of this large change in morphology, we conduct Raman spectroscopic characterization before and after plasma exposure for both single-layer and bilayer graphene ( Figure 1c) (more information in Figure S2, Supporting Information). The absence of a Raman D-peak in pristine graphene signifies the high quality of the employed graphene.…”

“…© 2020 Wiley-VCH GmbH gasses [17,22] and highlights the unique combination of physical and chemical processes involved (more details in Figure S3, Supporting Information). Surprisingly, however, bilayer graphene is retained after the etching process although it exhibits a prominent D peak at 1352 cm −1 indicating the appearance of atomic-scale defects and sp 3 bonding.…”

Atomistic Insight into the Formation of Metal-Graphene One-Dimensional Contacts

“…According to our energetics considerations (see details in Ref. [39]), monoand difluorination [48], and mono-oxidation are found to be the most favorable chemical edge modifications. For each of these contaminant groups, we mimic the experimental fabrication process by investigating the contact formation upon approach of the metal to the graphenic system (see the details in the Methods section).…”

“…4(a). Thus, the F 2 modification of the graphene edge, despite being energetically more favorable for isolated graphene [48], is not likely to occur under the influence of transitionmetal electrodes in edge-contacted topology. When Au is used, instead, the graphene edges (clean or contaminated) are not modified by the interaction with the metal.…”

Integration of ammonia-plasma-functionalized graphene nanodiscs as charge trapping centers for nonvolatile memory applications

“…It has been demonstrated that a large memory window can be obtained using the Ge-NPs embedded in dielectrics [20,21]. Moreover, the spatial distribution of discrete charge Several studies have demonstrated that nano-sized graphene structures, graphene nanodots, exhibit unique electronic properties on the edges, i.e., with zigzag and armchair structures [30][31][32][33][34][35], which are particularly favorable for functionalization. These graphenebased nanodots were patterned using either silica nanodots or polystyrene spheres as an etching mask [36][37][38].…”