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

2009 ◽  
Vol 94 (12) ◽  
pp. 122111 ◽  
Author(s):  
Y. H. Lu ◽  
R. Q. Wu ◽  
L. Shen ◽  
M. Yang ◽  
Z. D. Sha ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Band Gap ◽  
Graphene Nanoribbon ◽  
Band Gap Engineering ◽  
Armchair Graphene Nanoribbon ◽  
Armchair Graphene

scholarly journals DFT Study of the Electronic Structure of Cubic-SiC Nanopores with a C-Terminated Surface

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
M. Calvino ◽  
A. Trejo ◽  
M. I. Iturrios ◽  
M. C. Crisóstomo ◽  
Eliel Carvajal ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Band Gap ◽  
Density Functional ◽  
Surface Passivation ◽  
Phase Changes ◽  
Surface Relaxation ◽  
Oh Radicals ◽  
Functional Theory ◽  
Band Gap Engineering ◽  
Chemical Surface

A study of the dependence of the electronic structure and energetic stability on the chemical surface passivation of cubic porous silicon carbide (pSiC) was performed using density functional theory (DFT) and the supercell technique. The pores were modeled by removing atoms in the [001] direction to produce a surface chemistry composed of only carbon atoms (C-phase). Changes in the electronic states of the porous structures were studied by using different passivation schemes: one with hydrogen (H) atoms and the others gradually replacing pairs of H atoms with oxygen (O) atoms, fluorine (F) atoms, and hydroxide (OH) radicals. The results indicate that the band gap behavior of the C-phase pSiC depends on the number of passivation agents (other than H) per supercell. The band gap decreased with an increasing number of F, O, or OH radical groups. Furthermore, the influence of the passivation of the pSiC on its surface relaxation and the differences in such parameters as bond lengths, bond angles, and cell volume are compared between all surfaces. The results indicate the possibility of nanostructure band gap engineering based on SiC via surface passivation agents.

Electron Tunneling Current in an n-p-n Bipolar Transistor Based on Armchair Graphene Nanoribbon by Using Airy-Wavefunction Approach

2015 ◽  
Vol 1112 ◽  
pp. 80-84
Author(s):  
Fatimah A. Noor ◽  
Rifky Syariati ◽  
Endi Suhendi ◽  
Mikrajuddin Abdullah ◽  
Khairurrijal
Keyword(s):  
Electron Tunneling ◽  
Tunneling Current ◽  
Band Gap Energy ◽  
Graphene Nanoribbon ◽  
Bipolar Transistor ◽  
Electron Effective Mass ◽  
Collector Voltage ◽  
Armchair Graphene Nanoribbon ◽  
Armchair Graphene ◽  
Emitter Voltage

We have developed a model of the tunneling current in n-p-n bipolar transistor based on armchair graphene nanoribbon (AGNR). Airy-wavefunction approach is employed to obtain electron transmittance, and the obtained transmittance is then used to obtain the tunneling current. The tunneling current is calculated for various variables such as base-emitter voltage, base-current voltage, and AGNR width. It is found that the tunneling current increases with increasing the base-emitter voltage or the base-collector voltage. This result is due to the lowered barrier height of the base region caused by the increase in the base-emitter voltage or the base-collector voltage. In addition, the tunneling current density increases with the width for narrow AGNR and, on the other hand, it decreases for wide AGNR. This finding might be due to the contributions of the band gap energy and the electron effective mass of AGNR which are inversely proportional to the AGNR width.

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