Effects of edge passivation by hydrogen on electronic structure of armchair graphene nanoribbon and band gap engineering

We investigated effects of hydrogen passivation of edges of armchair graphene nanoribbons (AGNRs) on their electronic properties using first-principles method. The calculated band gaps of the AGNRs vary continually over a range of 1.6 eV as a function of a percentage of sp3-like bonds at the edges. This provides a simple way for band gap engineering of graphene as the relative stability of sp2 and sp3-like bonds at the edges of the AGNRs depends on the chemical potential of hydrogen gas, and the composition of the sp2 and sp3-like bonds at the edges of the AGNRs can be easily controlled experimentally via temperature and pressure of H2 gas.

[1]  Seifert,et al.  Construction of tight-binding-like potentials on the basis of density-functional theory: Application to carbon. , 1995, Physical review. B, Condensed matter.

[2]  C. W. J. Beenakker,et al.  Valley filter and valley valve in graphene , 2007 .

[3]  B. Delley.  An all‐electron numerical method for solving the local density functional for polyatomic molecules , 1990 .

[4]  P. Kim,et al.  Temperature-dependent transport in suspended graphene. , 2008, Physical review letters.

[5]  P. Kim,et al.  Energy band-gap engineering of graphene nanoribbons. , 2007, Physical review letters.

[6]  B. Delley.  From molecules to solids with the DMol3 approach , 2000 .

[7]  D. R. Strachan,et al.  Crystallographic etching of few-layer graphene. , 2008, Nano letters.

[8]  Andre K. Geim,et al.  Electric Field Effect in Atomically Thin Carbon Films , 2004, Science.

[9]  S. Louie,et al.  Energy gaps in graphene nanoribbons. , 2006, Physical Review Letters.

[10]  D. Goldhaber-Gordon,et al.  Transport measurements across a tunable potential barrier in graphene. , 2007, Physical review letters.

[11]  Jie Chen,et al.  Tuning the electronic structure of graphene nanoribbons through chemical edge modification : a theoretical study , 2007, cond-mat/0703794.

[12]  Burke,et al.  Generalized Gradient Approximation Made Simple. , 1996, Physical review letters.

[13]  S. Okada.  Energetics of nanoscale graphene ribbons : Edge geometries and electronic structures , 2008 .

[14]  K. Novoselov,et al.  Detection of individual gas molecules adsorbed on graphene. , 2006, Nature materials.

[15]  C. Berger,et al.  Electronic Confinement and Coherence in Patterned Epitaxial Graphene , 2006, Science.

[16]  Xu Du,et al.  Approaching ballistic transport in suspended graphene. , 2008, Nature nanotechnology.