A DFT Study of B, N and BN Doped Graphene

2014 ◽  
Vol 1701 ◽  
Author(s):  
Pooja Rani ◽  
V. K. Jindal

ABSTRACTWe have made a density functional study of the structural and electronic properties of B or N (individual) doped and BN co-doped graphene. The effect of doping has been studied by incorporating the doping concentration amount varying from 2% (one atom of the dopant in 50 host atoms) to 12 % atomic concentration in case of individual doping and from 4% (2 atoms of the dopant in 50 host atoms) to 24 % in case of co-doping, at the same time, altering different doping sites for the same concentration of substitutional doping. We made use of VASP (Vienna Ab-Initio Simulation Package) software based on density functional theory to perform all calculations. While the resulting geometries do not show much of distortion on doping, the electronic properties show a transition from semimetal to semiconductor with increasing number of dopants. The study shows that the BN doping introduces the band gap at the Fermi level unlike individual B and N doping which causes the shifting of Fermi level above or below the Dirac point. It is observed that not only concentration but position of B and N atoms in the hetero-structure also affects the value of band gap introduced.

2007 ◽  
Vol 996 ◽  
Author(s):  
Peter Broqvist ◽  
Alfredo Pasquarello

AbstractWe study structural and electronic properties of the oxygen vacancy in monoclinic HfO2 for five different charge states. We use a hybrid density functional to accurately reproduce the experimental band gap. To compare with measured defect levels, we determine total-energy differences appropriate to the considered experiments. Our results show that the oxygen vacancy can consistently account for the defect levels observed in optical absorption, direct electron injection, and trap-assisted conduction experiments.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
E. Klontzas ◽  
E. Tylianakis ◽  
V. Varshney ◽  
A. K. Roy ◽  
G. E. Froudakis

Abstract The structural and electronic properties of molecularly pillared graphene sheets were explored by performing Density Functional based Tight Binding calculations. Several different architectures were generated by varying the density of the pillars, the chemical composition of the organic molecule acting as a pillar and the pillar distribution. Our results show that by changing the pillars density and distribution we can tune the band gap transforming graphene from metallic to semiconducting in a continuous way. In addition, the chemical composition of the pillars affects the band gap in a lesser extent by introducing additional states in the valence or the conduction band and can act as a fine band gap tuning. These unique electronic properties controlled by design, makes Mollecular Pillared Graphene an excellent material for flexible electronics.


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