Strain induced new phase and indirect–direct band gap transition of monolayer InSe

2017 ◽  
Vol 19 (32) ◽  
pp. 21722-21728 ◽  
Author(s):  
Ting Hu ◽  
Jian Zhou ◽  
Jinming Dong
Keyword(s):  
Band Gap ◽  
Plane Strain ◽  
First Principles ◽  
First Principles Calculations ◽  
Direct Band Gap ◽  
Direct Band ◽  
New Phase

The effect of in-plane strain on monolayer InSe has been systematically investigated by using first-principles calculations.

Strain-induced semimetal-to-semiconductor transition and indirect-to-direct band gap transition in monolayer 1T-TiS2

RSC Advances ◽  
2015 ◽  
Vol 5 (102) ◽  
pp. 83876-83879 ◽  
Author(s):  
Chengyong Xu ◽  
Paul A. Brown ◽  
Kevin L. Shuford
Keyword(s):  
Band Gap ◽  
Electronic Properties ◽  
Plane Strain ◽  
Material Properties ◽  
First Principles ◽  
Tensile Strain ◽  
First Principles Calculations ◽  
Direct Band Gap ◽  
Direct Band ◽  
Uniform Plane

We have investigated the effect of uniform plane strain on the electronic properties of monolayer 1T-TiS2using first-principles calculations. With the appropriate tensile strain, the material properties can be transformed from a semimetal to a direct band gap semiconductor.

First principles study of silicene symmetrically and asymmetrically functionalized with halogen atoms

RSC Advances ◽  
2016 ◽  
Vol 6 (98) ◽  
pp. 95846-95854 ◽  
Author(s):  
Wencheng Tang ◽  
Minglei Sun ◽  
Qingqiang Ren ◽  
Yajun Zhang ◽  
Sake Wang ◽  
...  
Keyword(s):  
Band Gap ◽  
First Principles ◽  
Tensile Strain ◽  
First Principles Calculations ◽  
Direct Band Gap ◽  
Halogen Atoms ◽  
First Principles Study ◽  
Direct Band

Using first principles calculations, we predicted that a direct-band-gap between 0.98 and 2.13 eV can be obtained in silicene by symmetrically and asymmetrically (Janus) functionalisation with halogen atoms and applying elastic tensile strain.

Penta-MX2 (M = Ni, Pd and Pt; X = P and As) monolayers: direct band-gap semiconductors with high carrier mobility

2019 ◽  
Vol 7 (12) ◽  
pp. 3569-3575 ◽  
Author(s):  
Shifeng Qian ◽  
Xiaowei Sheng ◽  
Xian Xu ◽  
Yuxiang Wu ◽  
Ning Lu ◽  
...  
Keyword(s):  
Band Gap ◽  
First Principles ◽  
Carrier Mobility ◽  
Two Dimensional ◽  
First Principles Calculations ◽  
Ring Network ◽  
Direct Band Gap ◽  
Direct Band ◽  
High Carrier Mobility ◽  
High Carrier

Two-dimensional binary MX2 (M = Ni, Pd and Pt; X = P and As) exhibiting a beautiful pentagonal ring network is discussed through first principles calculations.

Direct band gap nature and optical response of BexMgyZn1−(x+y)Se

2016 ◽  
Vol 30 (03) ◽  
pp. 1650007
Author(s):  
Naeemullah ◽  
G. Murtaza ◽  
R. Khenata ◽  
S. Bin Omran
Keyword(s):  
Band Gap ◽  
First Principles ◽  
Density Functional ◽  
Experimental Measurements ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Direct Band Gap ◽  
Direct Band ◽  
First Time ◽  
Ultraviolet Energy

For the first time, the electronic and optical properties of the quaternary Be[Formula: see text]Mg[Formula: see text]Zn[Formula: see text]Se alloy have been investigated using first-principles calculations within the framework of density functional theory (DFT). Variations in the direct band gap with the change in [Formula: see text] and [Formula: see text] compositions show agreement with the experimental measurements. Evaluation of the dielectric function and refractive index reveals the optical activity in the visible and ultraviolet energy regions.

Phase stability, mechanical and optoelectronic properties of two novel phases of AlN

2017 ◽  
Vol 31 (18) ◽  
pp. 1750201 ◽  
Author(s):  
Ruike Yang ◽  
Chuanshuai Zhu ◽  
Qun Wei ◽  
Zheng Du
Keyword(s):  
Band Gap ◽  
First Principles ◽  
Semiconductor Device ◽  
Phonon Dispersion ◽  
Ambient Pressure ◽  
Optoelectronic Device ◽  
First Principles Calculations ◽  
Covalent Bonds ◽  
Direct Band Gap ◽  
Direct Band

Two novel aluminum nitride (which is bct-AlN at ambient pressure, and h-AlN at higher pressure) were predicted using first-principles calculations. The mechanical and phonon dispersion results indicate that bct-AlN is mechanically and dynamically stable at zero pressure, h-AlN phase can be stabilized by increasing pressure and it is mechanically and dynamically stable at 10 GPa. bct-AlN is more favorable than rs-AlN in thermodynamics at ambient pressure. Our calculated band gap of bct-AlN is 5.85 eV. It can be used as semiconductor device and optoelectronic device due to its inherent wide direct band gap. For bct-AlN, the shortest Al–N bond length is 1.8476 Å and its bond order index is 1.28, which shows that strong covalent bonds are formed between Al atoms and N atoms. Moreover, the anisotropy of Young’s modulus and optical properties can be noticed obviously for bct-AlN.

Indirect-Direct Band Gap Transition by Van Der Waals Interaction Engineering in MoS2/WS2 Bilayer Heterojunction

2014 ◽  
Vol 614 ◽  
pp. 70-74 ◽  
Author(s):  
Hai Ning Cao ◽  
Zhi Ya Zhang ◽  
Ming Su Si ◽  
Feng Zhang ◽  
Yu Hua Wang
Keyword(s):  
Band Gap ◽  
First Principles ◽  
Electronic Structures ◽  
Density Functional ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Direct Band Gap ◽  
The Density Functional Theory ◽  
Direct Band ◽  
Electric Filed

First principles calculations based on the density functional theory (DFT) are employed to estimate the electronic structures of bilayer heterostructure of MoS2/WS2. The dependences of the band structures on external electric field and interlayer separation are evaluated. The external electric filed induces a semiconductor-metal transition. At the same time, a larger interlayer separation, corresponding to a weaker interlayer interaction, makes an indirect-direct band gap transition happen for the heterojunction. Our results demonstrate that electronic structure tailoring of two-dimensional layered materials should include both spatial symmetry control and interlayer vdW interactions engineering.

Graphene stabilized high-κ dielectric Y2O3 (111) monolayers and their interfacial properties

RSC Advances ◽  
2015 ◽  
Vol 5 (102) ◽  
pp. 83588-83593 ◽  
Author(s):  
Ting Ting Song ◽  
Ming Yang ◽  
Martin Callsen ◽  
Qing Yun Wu ◽  
Jun Zhou ◽  
...  
Keyword(s):  
Band Gap ◽  
First Principles ◽  
Interfacial Properties ◽  
First Principles Calculations ◽  
Direct Band Gap ◽  
Direct Band

In this study, via first-principles calculations, we predict a stable planar Y2O3 (111) monolayer with a direct band gap of 3.96 eV. This high-κ dielectric monolayer can be further stabilized by a graphene substrate.

Electronic and optical properties of Janus Monolayers MoXB2(X=S,Se): First-principles prediction

2021 ◽  
Author(s):  
Qingwen Lan ◽  
Changpeng Chen ◽  
Tian Qin
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
First Principles ◽  
First Principles Calculations ◽  
Electronic And Optical Properties ◽  
Direct Band Gap ◽  
Direct Band ◽  
Indirect Band Gap ◽  
The Stability ◽  
Optical Calculation

By means of comprehensive first-principles calculations, we studied the geometric structure, the stability and electronic properties of the new two-dimensional(2D) Janus MoXB2(X=S, Se) monolayers. Our calculations demonstrated that the predicted Janus MoXB2 monolayers are all stable semiconductors with direct band gap. In this paper, we focus on impacts upon the electronic and optical properties of the MoXB2 monolayers under the different biaxial strains. With the compressive stress increases, the MoXB2 monolayers would become indirect band gap semiconductors, and then behave as semimetal. While under tensile strain, MoXB2 still maintain direct band gap. In addition, the optical calculation shows that biaxial strain leads to blue shifts in the optical absorption and reflectivity. The result indicates that MoXB2 may be promised nano candidate materials in optoelectronic devices.

FIRST-PRINCIPLES CALCULATIONS FOR THE STRUCTURAL AND ELECTRONIC PROPERTIES OF ScxAl1-xN ALLOYS

2013 ◽  
Vol 24 (10) ◽  
pp. 1350074 ◽  
Author(s):  
REZEK MOHAMMAD ◽  
ŞENAY KATIRCIOĞLU
Keyword(s):  
Band Gap ◽  
Electronic Properties ◽  
Rock Salt ◽  
First Principles ◽  
First Principles Calculations ◽  
Electronic Band ◽  
Direct Band Gap ◽  
Near Ultraviolet ◽  
Structural And Electronic Properties ◽  
Direct Band

The first-principles calculations based on Density Functional Theory (DFT) within generalized gradient approximation (GGA) of Engel–Vosko–Perdew–Wang and modified exact exchange potential of Becke–Johnson have been introduced for the structural and electronic properties of the Sc x Al 1-x N alloys, respectively. The present lattice constants calculated for the ScAlN alloys and the end compounds ( AlN and ScN ) are found to be in very good agreement with the available experimental and theoretical ones. The stable ground state structures of the Sc x Al 1-x N alloys are determined to be wurtzite for the Sc concentration less than ~0.403 and rock-salt for the higher Sc concentrations. The present electronic band structure calculations within Becke–Johnson scheme are found to be capable of providing energy band gaps of the AlN and ScN compounds very close to the ones of the available experiments and expensive calculations. According to the calculations of Becke–Johnson potential, the Sc x Al 1-x N alloys in the wurtzite and zinc-blende structures are direct band gap materials for the Sc concentrations in the ranges of (0.056 ≤ x ≤ 0.833) and (0.03125 ≤ x ≤ 0.0625, 0.375 ≤ x ≤ 0.96875), respectively. However, the ScAlN alloys in the rock-salt phase are determined to be direct band gap materials for total range of the Sc concentration considered in this work. While the energy gaps of the RS- AlScN alloys are found to be extending from near ultraviolet to near infrared with a large (negative) bowing, the ones of the WZ- AlScN and ZB- AlScN alloys are determined to be varying in a small energy range around near ultraviolet with a small (negative) bowing.

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