Electric Field Tunable Band Gap in Bi-Axially Strained Graphene/Hexagonal Boron Nitride Super-Lattice

2013 ◽  
Vol 1 (4) ◽  
pp. 200-206 ◽  
Author(s):  
Jiangtao Wu ◽  
Baolin Wang ◽  
Yujie Wei ◽  
Ronggui Yang ◽  
Mildred Dresselhaus

2011 ◽  
Vol 1307 ◽  
Author(s):  
Samir S. Coutinho ◽  
David L. Azevedo ◽  
Douglas S. Galvão

ABSTRACTRecently, several experiments and theoretical studies demonstrated the possibility of tuning or modulating band gap values of nanostructures composed of bi-layer graphene, bi-layer hexagonal boron-nitride (BN) and hetero-layer combinations. These triple layers systems present several possibilities of stacking. In this work we report an ab initio (within the formalism of density functional theory (DFT)) study of structural and electronic properties of some of these stacked configurations. We observe that an applied external electric field can alter the electronic and structural properties of these systems. With the same value of the applied electric field the band gap values can be increased or decreased, depending on the layer stacking sequences. Strong geometrical deformations were observed. These results show that the application of an external electric field perpendicular to the stacked layers can effectively be used to modulate their inter-layer distances and/or their band gap values.


Author(s):  
А.А. Андронов ◽  
В.И. Позднякова

Abstract We interpret the recent observations of Otsuji’s team (Sendai) on switching from absorption to amplification at a temperature of T = 300 K during the passage of terahertz radiation through hexagonal boron nitride–graphene sandwiches with multiple gates on the surface with an increase in the electric field in graphene. It is shown that these effects are related to dispersion and negative conductivity near the transit-time frequency of electrons in momentum space under streaming (anisotropic distribution) in graphene in a strong electric field. On the basis of these data, a universal tunable terahertz source is proposed, which has the form of a graphene-containing sandwich with a high-resistance silicon wafer (a cavity) with an applied voltage. This terahertz cavity is a complete analog of the microwave generator implemented on an InP chip by Vorobev’s team (St. Petersburg).


Carbon ◽  
2014 ◽  
Vol 74 ◽  
pp. 139-145 ◽  
Author(s):  
Won-Jun Jang ◽  
Howon Kim ◽  
Yong-Ro Shin ◽  
Min Wang ◽  
Sung Kyu Jang ◽  
...  

2018 ◽  
Vol 20 (42) ◽  
pp. 26934-26946 ◽  
Author(s):  
Jiangni Yun ◽  
Yanni Zhang ◽  
Yanbing Ren ◽  
Manzhang Xu ◽  
Junfeng Yan ◽  
...  

Stacking sequences, external strain and a vertical electric field can be used to effectively modulate the electronic structures of graphyne-based homo- and hetero-structures.


Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1026
Author(s):  
Mohammad Taghi Ahmadi ◽  
Ahmad Razmdideh ◽  
Seyed Saeid Rahimian Koloor ◽  
Michal Petrů

The absence of a band gap in graphene is a hindrance to its application in electronic devices. Alternately, the complete replacement of carbon atoms with B and N atoms in graphene structures led to the formation of hexagonal boron nitride (h-BN) and caused the opening of its gap. Now, an exciting possibility is a partial substitution of C atoms with B and N atoms in the graphene structure, which caused the formation of a boron nitride composite with specified stoichiometry. BC2N nanotubes are more stable than other triple compounds due to the existence of a maximum number of B–N and C–C bonds. This paper focused on the nearest neighbor’s tight-binding method to explore the dispersion relation of BC2N, which has no chemical bond between its carbon atoms. More specifically, the band dispersion of this specific structure and the effects of energy hopping in boron–carbon and nitrogen–carbon atoms on the band gap are studied. Besides, the band structure is achieved from density functional theory (DFT) using the generalized gradient approximations (GGA) approximation method. This calculation shows that this specific structure is semimetal, and the band gap energy is 0.167 ev.


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