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تسجيل مستخدم جديدChemical Functionalization of Graphene Nanoribbons by Carboxyl Groups on Stone-Wales Defects
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Using the density functional theory, we have demonstrated the chemical functionalization of semiconducting graphene nanoribbons (GNRs) with Stone-Wales (SW) defects by carboxyl (COOH) groups. It is found that the geometrical structures and electronic properties of the GNRs changed significantly, and the electrical conductivity of the system could be considerably enhanced by mono-adsorption and double-adsorption of COOH, which sensitively depends upon the axial concentration of SW defects COOH pairs (SWDCPs). With the increase of the axial concentration of SWDCPs, the system would transform from semiconducting behavior to p-type metallic behavior. This fact makes GNRs a possible candidate for chemical sensors and nanoelectronic devices based on graphene nanoribbons.
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Stone-Wales (SW) defects are favorably existed in graphenelike materials with honeycomb lattice structure and potentially employed to change the electronic properties in band engineering. In this paper, we investigate structural and electronic proper
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During the synthesis of ultra-thin materials with hexagonal lattice structure Stone-Wales (SW) type of defects are quite likely to be formed and the existence of such topological defects in the graphene-like structures results in dramatical changes o
f their electronic and mechanical properties. Here we investigate the formation and reactivity of such SW defects in silicene. We report the energy barrier for the formation of SW defects in freestanding (~2.4 eV) and Ag(111)-supported (~2.8 eV) silicene and found it to be significantly lower than in graphene (~9.2 eV). Moreover, the buckled nature of silicene provides a large energy barrier for the healing of the SW defect and therefore defective silicene is stable even at high temperatures. Silicene with SW defects is semiconducting with a direct bandgap of 0.02 eV and this value depends on the concentration of defects. Furthermore, nitrogen substitution in SW defected silicene shows that the defect lattice sites are the least preferable substitution locations for the N atoms. Our findings show the easy formation of SW defects in silicene and also provide a guideline for bandgap engineering in silicene-based materials through such defects.
A two-dimensional carbon allotrope, Stone-Wales graphene, is identified in stochastic group and graph constrained searches and systematically investigated by first-principles calculations. Stone-Wales graphene consists of well-arranged Stone-Wales de
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Observations of topological defects associated with Stone-Wales-type transformations (i.e., bond rotations) in high resolution transmission electron microscopy (HRTEM) images of carbon nanostructures are at odds with the equilibrium thermodynamics of
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