scholarly journals First-principles calculations of the phase diagrams and band gaps in CuInSe2-CuGaSe2and CuInSe2-CuAlSe2pseudobinary systems

2012 ◽  
Vol 85 (3) ◽  
Author(s):  
Yu Kumagai ◽  
Yoshito Soda ◽  
Fumiyasu Oba ◽  
Atsuto Seko ◽  
Isao Tanaka
Keyword(s):  
Phase Diagrams ◽  
First Principles ◽  
Band Gaps ◽  
First Principles Calculations

scholarly journals First principles study of structure, electronic and optical properties of Y3Fe5O12 in cubic and trigonal phases

2015 ◽  
Vol 33 (1) ◽  
pp. 169-174 ◽  
Author(s):  
Shen Tao ◽  
Hu Chao ◽  
Dai Hailong ◽  
Yang Wenlong ◽  
Liu Hongchen ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Energy Loss ◽  
First Principles ◽  
Structural Parameters ◽  
Band Gaps ◽  
First Principles Calculations ◽  
Electronic And Optical Properties ◽  
Direct Band ◽  
Experimental Values

AbstractFirst principles calculations have been performed to investigate the structure, electronic and optical properties of Y3Fe5O12. Both the cubic and trigonal phases have been considered in our calculation. The calculated structural parameters are slightly larger than the experimental values. The band structures show that Y3Fe5O12 in cubic and trigonal phases have direct band gaps of 0.65 and 0.17 eV. The calculations of dielectric function, absorption, extinction coefficient, refractive index, energy loss function and reflectivity are presented.

Widely tunable band gaps of graphdiyne: an ab initio study

2014 ◽  
Vol 16 (19) ◽  
pp. 8935-8939 ◽  
Author(s):  
Jahyun Koo ◽  
Minwoo Park ◽  
Seunghyun Hwang ◽  
Bing Huang ◽  
Byungryul Jang ◽  
...  
Keyword(s):  
Ab Initio ◽  
First Principles ◽  
Atomic Layer ◽  
Band Gaps ◽  
Two Dimensional ◽  
First Principles Calculations ◽  
Ab Initio Study ◽  
Carbon Networks ◽  
Hybrid Carbon

Functionalization of graphdiyne, a two-dimensional atomic layer of sp–sp2 hybrid carbon networks, was investigated through first-principles calculations.

First-principles study on the geometry and electronic structures of IIIA atoms doped α-Al2O3:VO

2014 ◽  
Vol 92 (10) ◽  
pp. 1135-1140 ◽  
Author(s):  
L. Ao ◽  
J.L. Nie ◽  
X. Xiang ◽  
X.T. Zu ◽  
J. Huang ◽  
...  
Keyword(s):  
Transition Metal ◽  
Oxygen Vacancy ◽  
Electronic Property ◽  
First Principles ◽  
Electronic Structures ◽  
Band Gaps ◽  
First Principles Calculations ◽  
Hexagonal Symmetry ◽  
Α Al2o3 ◽  
Metal Doped

We investigate the geometry and electronic structures of α-Al2O3:VO + AlX systems based on first-principles calculations where VO represents one oxygen vacancy and AlX stands for IIIA atoms (B, Ga, In, and Tl) substituting of one Al atom. It is found that all the aluminates maintain the hexagonal symmetry as the pure α-Al2O3 structure and the lattice parameters a, b, and c are expanded with the increase of the IIIA atoms radius. The electronic property analysis indicates that the band gaps are considerably reduced and the reductions are also related to the radius of doping atoms. But unlike the situation of transition metal doped α-Al2O3 the decreases of the band gap are not due to the spreading of d states, but are mainly owing to the ns states at the bottom of the conduction band.

Transition of wide-band gap semiconductor h-BN(BN)/P heterostructure via single-atom-embedding

2020 ◽  
Vol 8 (28) ◽  
pp. 9755-9762 ◽  
Author(s):  
Itsuki Miyazato ◽  
Tanveer Hussain ◽  
Keisuke Takahashi
Keyword(s):  
Boron Nitride ◽  
Band Gap ◽  
First Principles ◽  
Wide Band ◽  
Band Gaps ◽  
Single Atom ◽  
First Principles Calculations ◽  
Optoelectronic Materials ◽  
Wide Band Gap

The band gaps in boron nitride/phosphorene (h-BN/P) heterostructures are investigated by single-atom-embedding via first principles calculations. The modified heterostructures are potential optoelectronic materials with tunable band gaps.

Carbon phosphide nanosheets and nanoribbons: insights on modulating their electronic properties by first principles calculations

2020 ◽  
Vol 22 (39) ◽  
pp. 22520-22528
Author(s):  
Tong Chen ◽  
Huili Li ◽  
Yuyuan Zhu ◽  
Desheng Liu ◽  
Guanghui Zhou ◽  
...  
Keyword(s):  
Band Gap ◽  
Electronic Properties ◽  
Electronic Transport ◽  
First Principles ◽  
Axial Strain ◽  
Band Gaps ◽  
First Principle ◽  
First Principles Calculations ◽  
Tunable Band Gap

We investigate the tunable band-gap semiconductor characteristics and electronic transport behaviors of 2D and quasi-1D CP derivatives by using first-principle methods. With bi-axial strain, the band gaps display an incremental trend from compression to stretching.

Thermodynamic Analysis of Steels by Incorporating First-Principles Calculations into the CALPHAD Approach

2007 ◽  
Vol 539-543 ◽  
pp. 2413-2418 ◽  
Author(s):  
Hiroshi Ohtani ◽  
N. Hanaya ◽  
Mitsuhiro Hasebe
Keyword(s):  
Phase Diagrams ◽  
Thermodynamic Analysis ◽  
First Principles ◽  
Experimental Information ◽  
Full Potential ◽  
Calphad Approach ◽  
First Principles Calculations ◽  
Plane Wave Method ◽  
Ternary Phase Diagrams ◽  
High Degree

A thermodynamic analysis of the Fe−M−P (M = Nb, Ti) ternary system has been performed by combining first-principles calculations with the CALPHAD approach. Because of the lack of experimental information available, thermodynamic properties of orthorhombic anti-PbCl2-type FeMP were evaluated using the Full Potential Linearized Augmented Plane Wave method, and the estimated values were introduced into a CALPHAD-type thermodynamic analysis. Applying this procedure, the phase diagrams of the Fe−M−P ternary phase diagrams whose contents are uncertain so far were calculated with a high degree of probability. Phase diagrams for high-purity ferritic stainless steels obtained following the same procedure are also presented.

scholarly journals Strain Engineered Band Gaps and Electronic Properties in PbPdO2 and PbPd0.75Co0.25O2 Slabs

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2002
Author(s):  
Yanmin Yang ◽  
Kehua Zhong ◽  
Guigui Xu ◽  
Jian-Min Zhang ◽  
Zhigao Huang
Keyword(s):  
Electronic Structure ◽  
Carrier Concentration ◽  
First Principles ◽  
Bond Angle ◽  
Charge Carrier Concentration ◽  
Band Gaps ◽  
First Principles Calculations ◽  
Potential Mechanism ◽  
Plane Anisotropy ◽  
External Strain

Electronic structure and corresponding electrical properties of PbPdO2 and PbPd0.75Co0.25O2 ultrathin slabs with (002) preferred orientation were systematically investigated using first-principles calculations. The calculated results revealed the strain induced evidently the changes of band structure and carrier concentration in both slabs. It was also found that PbPdO2 and PbPd0.75Co0.25O2 ultrathin slabs exhibited evident differences in the external strain dependence of the band gap and charge carrier concentration, which was strongly dependent on bond angle and bond length induced by in-plane anisotropy strain. Interestingly, the carrier concentration of the PbPd0.75Co0.25O2 slab could increase up to 5–6 orders of magnitude with the help of external strain, which could explain the potential mechanism behind the observed colossal strain-induced electrical behaviors. This work demonstrated that the influence of the doping effect in the case of PbPdO2 could be a potentially fruitful approach for the development of promising piezoresistive materials.

ELECTRONIC AND MAGNETIC PROPERTIES OF SILICENE AND SILICANE NANORIBBONS

2013 ◽  
Vol 02 (02) ◽  
pp. 1350011 ◽  
Author(s):  
KAI LI ◽  
ANNA SHIN HWA LEE ◽  
YONG-WEI ZHANG ◽  
HUI PAN
Keyword(s):  
Magnetic Properties ◽  
First Principles ◽  
Magnetic Moments ◽  
Ground States ◽  
Band Gaps ◽  
Metastable States ◽  
First Principles Calculations ◽  
Ribbon Width ◽  
Electronic And Magnetic Properties ◽  
Silicene Nanoribbons

In this paper, first-principles calculations are carried out to study the electronic and magnetic properties of silicene and silicane nanoribbons, with and without H -passivation at the edges. We predict that the armchair nanoribbons are nonmagnetic and semiconducting. Interestingly, the band gaps of armchair silicene nanoribbons show oscillating behavior as the ribbon width increases. When their edges are passivated with H atoms, However, the oscillating phase is reversed. The zigzag nanoribbons are anti-ferromagnetic and semiconducting in their ground states, except that the zigzag silicane nanoribbons with edges passivated by H atoms are nonmagnetic. The zigzag silicane nanoribbons with bare edges show the highest magnetic moments in their ground states. The band gaps of zigzag nanoribbons in their ground states decrease with the increment of width. The metastable states of zigzag silicene nanoribbons are ferromagnetic and metallic. The zigzag silicane nanoribbons with bare edges are ferromagnetic and semiconducting in their metastable states. The silicene/silicane nanoribbons with attractive functions, which are achievable by edge engineering or external fields, may be applied to spintronic technologies and nanodevices.

Elastic Properties and Electronic Structure of WS2 under Pressure from First-principles Calculations

2017 ◽  
Vol 72 (4) ◽  
pp. 295-301 ◽  
Author(s):  
Li Li ◽  
Zhao-Yi Zeng ◽  
Ting Liang ◽  
Mei Tang ◽  
Yan Cheng
Keyword(s):  
Density Of States ◽  
First Principles ◽  
External Pressure ◽  
Band Gaps ◽  
Partial Density ◽  
Total Density ◽  
Transition Metal Dichalcogenide ◽  
First Principles Calculations ◽  
First Time ◽  
Total Density Of States

AbstractThe influence of pressure on the elastic and mechanical properties of the hexagonal transition-metal dichalcogenide WS2 is investigated using the first-principles calculations. With the increase in pressure, the lattice parameters and the volume of WS2 decrease, which is exactly in agreement with the available experimental data and other calculated results. The elastic constants Cij, bulk modulus B, shear modulus G, Young’s modulus E, and Poisson’s ratio σ of WS2 also increase with pressure. At last, for the first time, the band gaps of energy, the partial density of states, and the total density of states under three different pressures are obtained and analysed. It is found that the band gap of WS2 decreases from 0.843 to 0 eV when the external pressure varies from 0 to 20 GPa, which implies that WS2 may transform from semiconductors to semimetal phase at a pressure about 20 GPa.

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