Theoretical study of corundum as an ideal gate dielectric material for graphene transistors

Abstract

Using physical insights and advanced first-principles calculations, we suggest that corundum (α-Al2O3) is an ideal gate dielectric material for graphene transistors. Clean interface exists between graphene and Al-terminated (or hydroxylated) Al2O3 and the valence band offsets for these systems are large enough to create injection barrier. Remarkably, a band gap of ∼ 180 meV can be induced in graphene layer adsorbed on Al-terminated surface with an electron effective mass of ∼ 8 × 10 −3 me. Moreover, the band gaps of graphene/Al2O3 system could be tuned by an external electric field for practical applications.

Origin of the significantly enhanced optical transitions in layered boron nitride

“…A 20Å vacuum region is included when we calculate the nanostructures. The pseudo-H method 7 is used to passivate the surfaces of BN quantum dot (QD), AlN thin film, and GaN thin film. Enough k-point sampling is used for the Brillouin-zone integration.…”

Sublattice-induced symmetry breaking and band-gap formation in graphene

“…There are various widely publicized approaches to engineering a band gap in graphene, such as strain engineering, 1-4 spatial restriction, for example via graphene nanoribbon fabrication, [5][6][7][8][9][10][11][12][13][14][15][16] controlling the density of electrons as in adsorbate hybridization, [17][18][19][20][21] and symmetry breaking, [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41] typically as a result of substrate interactions. All have major aws when the goal is retention of the unique properties of graphene while opening a band gap.…”

Exceptional Optoelectronic Properties of Hydrogenated Bilayer Silicene

“…Projectoraugmented-wave (PAW) potentials are used to describe the core electrons, and the generalized gradient approximation (GGA) with the Perdew-Burke-Ernzerhof (PBE) functional is selected in our calculations. The effect of van de Waals (vdW) interactions is taken into account by using the empirical correction scheme of Grimme (DFT þ D=PBE) [48], which has proved to be successful in describing various layered structures [49,50]. The kinetic-energy cutoff for the plane-wave basis is set to 400 eV.…”