scholarly journals Tuning Electronic Properties of the SiC-GeC Bilayer by External Electric Field: A First-Principles Study

Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 309
Author(s):  
Min Luo ◽  
Bin Yu ◽  
Yu-e Xu
Keyword(s):  
Band Structure ◽  
Electric Field ◽  
Fermi Level ◽  
Electronic Properties ◽  
External Electric Field ◽  
Valence Band ◽  
Conduction Band ◽  
First Principles ◽  
First Principles Calculations ◽  
Direct Bandgap

First-principles calculations were used to investigate the electronic properties of the SiC/GeC nanosheet (the thickness was about 8 Å). With no electric field (E-field), the SiC/GeC nanosheet was shown to have a direct bandgap of 1.90 eV. In the band structure, the valence band of the SiC/GeC nanosheet was mainly made up of C-p, while the conduction band was mainly made up of C-p, Si-p, and Ge-p, respectively. Application of the E-field to the SiC/GeC nanosheet was found to facilitate modulation of the bandgap, regularly reducing it to zero, which was linked to the direction and strength of the E-field. The major bandgap modulation was attributed to the migration of C-p, Si-p, and Ge-p orbitals around the Fermi level. Our conclusions might give some theoretical guidance for the development and application of the SiC/GeC nanosheet.

scholarly journals Electric field induced electronic properties modification of ZrS2/HfS2 van der Waals heterostructure

RSC Advances ◽  
2017 ◽  
Vol 7 (24) ◽  
pp. 14625-14630 ◽  
Author(s):  
Jimin Shang ◽  
Shuai Zhang ◽  
Xuerui Cheng ◽  
Zhongming Wei ◽  
Jingbo Li
Keyword(s):  
Electric Field ◽  
Electronic Properties ◽  
External Electric Field ◽  
First Principles ◽  
Van Der Waals ◽  
First Principles Calculations ◽  
Van Der Waals Heterostructure

By using first-principles calculations, we investigate the electronic properties of a ZrS2/HfS2 heterostructure modulated by an external electric field.

Effects of n-Type Dopants on Electronic Properties in 4H-SiC

2015 ◽  
Vol 645-646 ◽  
pp. 325-329
Author(s):  
Jin Long Tang ◽  
Jun Nan Zhong ◽  
Cai Wen
Keyword(s):  
Band Structure ◽  
Fermi Level ◽  
Band Gap ◽  
Electronic Properties ◽  
Density Of States ◽  
First Principles ◽  
Electronic Structures ◽  
Doping Concentration ◽  
Impurity Level ◽  
First Principles Calculations

Based on first-principles calculations, we have investigated atomic and electronic structures of 4H-SiC crystal doped by N, P and As elements as n-type dopants. We have obtained the bond lengths of the optimization system, as well as the impurity levels, the band structure and the density of states. The results show that the higher impurity level above the Fermi level is observed when 4H-SiC doped by N with concentration as 6.25% in these dopants, and the band gap of 4H-SiC decreases while the doping concentration or the atomic number of dopant increases.

Electric field induced insulator to metal transition in a buckled GaAs monolayer

RSC Advances ◽  
2016 ◽  
Vol 6 (58) ◽  
pp. 52920-52924 ◽  
Author(s):  
Bhagwati Prasad Bahuguna ◽  
L. K. Saini ◽  
Brajesh Tiwari ◽  
R. O. Sharma
Keyword(s):  
Electric Field ◽  
Electronic Properties ◽  
External Electric Field ◽  
First Principles ◽  
Two Dimensional ◽  
First Principles Calculations

We investigate the electronic properties of two-dimensional buckled honeycomb GaAs in the presence of an external electric field using first principles calculations.

scholarly journals First-Principles Study on the Stabilities, Electronic and Optical Properties of GexSn1-xSe Alloys

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 876 ◽  
Author(s):  
Qi Qian ◽  
Lei Peng ◽  
Yu Cui ◽  
Liping Sun ◽  
Jinyan Du ◽  
...  
Keyword(s):  
Optical Properties ◽  
Solar Cells ◽  
Band Gap ◽  
Electronic Properties ◽  
First Principles ◽  
Future Application ◽  
First Principles Calculations ◽  
Electronic And Optical Properties ◽  
Direct Bandgap ◽  
The Future

We systematically study, by using first-principles calculations, stabilities, electronic properties, and optical properties of GexSn1-xSe alloy made of SnSe and GeSe monolayers with different Ge concentrations x = 0.0, 0.25, 0.5, 0.75, and 1.0. Our results show that the critical solubility temperature of the alloy is around 580 K. With the increase of Ge concentration, band gap of the alloy increases nonlinearly and ranges from 0.92 to 1.13 eV at the PBE level and 1.39 to 1.59 eV at the HSE06 level. When the Ge concentration x is more than 0.5, the alloy changes into a direct bandgap semiconductor; the band gap ranges from 1.06 to 1.13 eV at the PBE level and 1.50 to 1.59 eV at the HSE06 level, which falls within the range of the optimum band gap for solar cells. Further optical calculations verify that, through alloying, the optical properties can be improved by subtle controlling the compositions. Since GexSn1-xSe alloys with different compositions have been successfully fabricated in experiments, we hope these insights will contribute to the future application in optoelectronics.

scholarly journals Rich p -type-doping phenomena in boron-substituted silicene systems

2020 ◽  
Vol 7 (12) ◽  
pp. 200723
Author(s):  
Hai Duong Pham ◽  
Wu-Pei Su ◽  
Thi Dieu Hien Nguyen ◽  
Ngoc Thanh Thuy Tran ◽  
Ming-Fa Lin
Keyword(s):  
Charge Transfer ◽  
Fermi Level ◽  
Charge Density ◽  
Electronic Properties ◽  
First Principles ◽  
Chemical Environment ◽  
First Principles Calculations ◽  
Density Distributions ◽  
Essential Properties ◽  
P Type

The essential properties of monolayer silicene greatly enriched by boron substitutions are thoroughly explored through first-principles calculations. Delicate analyses are conducted on the highly non-uniform Moire superlattices, atom-dominated band structures, charge density distributions and atom- and orbital-decomposed van Hove singularities. The hybridized 2 p z –3 p z and [2s, 2 p x , 2 p y ]–[3s, 3 p x , 3 p y ] bondings, with orthogonal relations, are obtained from the developed theoretical framework. The red-shifted Fermi level and the modified Dirac cones/ π bands/ σ bands are clearly identified under various concentrations and configurations of boron-guest atoms. Our results demonstrate that the charge transfer leads to the non-uniform chemical environment that creates diverse electronic properties.

Strain engineering and electric field tunable of the electronic properties of two-dimensional ZnGeN2 monolayer

2021 ◽  
Author(s):  
Thi Nga Do ◽  
Son-Tung Nguyen ◽  
Khang Pham
Keyword(s):  
Electric Field ◽  
Electronic Properties ◽  
First Principles ◽  
Strain Engineering ◽  
Two Dimensional ◽  
First Principles Calculations ◽  
Structural And Electronic Properties

In this work, by means of the first-principles calculations, we investigate the structural and electronic properties of a two-dimensional ZnGeN2 monolayer as well as the effects of strains and electric...

The electric field modulation of electronic properties in a type-II phosphorene/PbI2 van der Waals heterojunction

2019 ◽  
Vol 21 (15) ◽  
pp. 7765-7772 ◽  
Author(s):  
Yuting Wei ◽  
Fei Wang ◽  
Wenli Zhang ◽  
Xiuwen Zhang
Keyword(s):  
Solar Energy ◽  
Electric Field ◽  
Electronic Properties ◽  
External Electric Field ◽  
Van Der Waals ◽  
Optoelectronic Devices ◽  
Band Alignment ◽  
Type Ii ◽  
Direct Bandgap ◽  
Field Modulation

The 0.52/0.83 eV direct bandgap of P/PbI2 possesses a type-II band alignment, can effectively be regulated to 0.90/1.54 eV using an external electric field in DFT/HSE06, and is useful for solar energy and optoelectronic devices.

POLARIZABILITY AND SHIELDING OF COAXIAL HYBRID DOUBLE-WALLED NANOTUBES: A FIRST-PRINCIPLES STUDY

2008 ◽  
Vol 07 (04) ◽  
pp. 793-803
Author(s):  
NUANXIANG LI ◽  
QUNXIANG LI ◽  
HAIBIN SU ◽  
Q. W. SHI ◽  
JINLONG YANG
Keyword(s):  
Carbon Nanotube ◽  
Boron Nitride ◽  
Electric Field ◽  
Electronic Properties ◽  
External Electric Field ◽  
First Principles ◽  
Electronic Structures ◽  
Outer Tube ◽  
Boron Nitride Nanotube ◽  
First Principles Study

First-principles studies on electronic structures, transverse polarizability, and shielding of two coaxial hybrid double-walled nanotubes consisting of carbon nanotube (CNT) and boron nitride nanotube (BNNT), namely CNT@BNNT and BNNT@CNT, are conducted. The interaction between inner and outer tubes is considerably weak. The polarizability of single-walled CNT is larger than that of single-walled BNNT due to the different electronic properties. In BNNT@CNT, the outer CNT with delocalized π-electrons character demonstrates a nearly complete shielding with the order of 90% of the inner BNNT from the transverse external electric field, while the outer BNNT has a relative small shielding of about 40% for the inner CNT in CNT@BNNT system. Moreover, the shielding of the outer tube can be appreciably enhanced by increasing the intertube separation.

scholarly journals Transformation of the Topological Phase and the Edge Modes of Double-Bilayer Bismuthene with Inter-Bilayer Spacing

Crystals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 266 ◽  
Author(s):  
Huanzhi Hu ◽  
Zhibin Shi ◽  
Peng Wang ◽  
Weiping Zhou ◽  
Tai-Chang Chiang ◽  
...  
Keyword(s):  
Phase Transition ◽  
Valence Band ◽  
Conduction Band ◽  
Topological Insulator ◽  
First Principles ◽  
Topological Phase ◽  
First Principles Calculations ◽  
Topological Phase Transition ◽  
Band Inversion ◽  
Band Insulator

The transformations of the topological phase and the edge modes of a double-bilayer bismuthene were investigated with first-principles calculations and Green’s function as the inter-bilayer spacing increased from 0 Å to 10 Å. At a critical spacing of 2 Å, a topological phase transition from a topological insulator to a band insulator resulting from a band inversion between the highest valence band and the second lowest conduction band, was observed, and this was understood based on the particular orbital characters of the band inversion involved states. The edge modes of double-bilayer bismuthene survived the phase transition. When d was 2 Å < d < 4 Å, the interaction between the edge modes of two separated bismuthene bilayers induced an anti-crossing gap and resulted in a trivial band connection. At and beyond 4 Å, the two bilayers behavior decoupled entirely. The results demonstrate the transformability of the topological phase and the edge modes with the inter-bilayer spacing in double-bilayer bismuthene, which may be useful for spintronic applications.

scholarly journals Applying first principles to study the structural, electronic, and magnetic properties of Pr adsorbed ASiNRs

2021 ◽  
pp. 53-63
Keyword(s):  
Magnetic Properties ◽  
Fermi Level ◽  
Bond Length ◽  
Electronic Properties ◽  
First Principles ◽  
Bond Angle ◽  
Structure Stability ◽  
Chemical Adsorption ◽  
First Principles Calculations ◽  
Silicene Nanoribbons

Applying first-principles calculations, the investigation of the geometrical and electronic properties of Pr adsorption armchair silicene nanoribbons structure has been established. The results show that the bandgap doped Pr has been changed, which is the case for chemical adsorption on the surface of ASiNRs; this material became metallic with the peak of valance band contact fermi level. Moreover, the survey to find the optimal height 1.82 Å of Pr and 2.24 Å bond length Si-Si, and Si-Si-Si bond angle 108005’, energy adsorption is -7.65 eV, buckling is 0.43 Å with structure stability close to the pristine case, has brought good results for actively creating newly applied materials for the spintronic and optoelectronics field in the future.

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