The Electronic Structure of Ga-Doped Hydrogen-Passivated Germanene: First Principle Study

2020 ◽  
Vol 833 ◽  
pp. 157-161
Author(s):  
Mauludi Ariesto Pamungkas ◽  
Husain ◽  
Achmad Kafi Shobirin ◽  
Tri Sugiono ◽  
Masruroh Masruroh
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Band Gap ◽  
Density Functional ◽  
Dft Calculation ◽  
First Principle ◽  
Hydrogen Passivation ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Hydrogenated Graphene

Germanene, which has the same structure as graphene, is an exciting novel 2D functionalized material that controls its band gap using functionalization. The effects of the Ga atom and hydrogen atoms on the structure of Ga-doped H-passivated germanene were investigated with a density functional theory (DFT) calculation. H-passivated germanene has a direct gap of 2.10 eV. Opening the band gap in the H-passivated germanene is due to transition from sp2 to sp3 orbital. Adsorption of the Ga adatom on H-site decrease the band gap to 1.38 eV. No interaction between Ga atoms and Hydrogen atoms was observed. Hence, their effects on the band structure of hydrogenated graphene were independent of each other. Our results suggest that hydrogen passivation combined with adsorption of the Ga adatoms could effectively control the band gap of germanene.

Modification on TiO2-a Photosensitive Material

2013 ◽  
Vol 579-580 ◽  
pp. 148-152
Author(s):  
Miao Sun ◽  
Yong Hu ◽  
Hua Guo
Keyword(s):  
Density Functional Theory ◽  
Band Gap ◽  
Light Absorption ◽  
Potential Application ◽  
Density Functional ◽  
First Principle ◽  
Functional Theory ◽  
Photosensitive Material ◽  
The Past ◽  
Light Area

TiO2, as photosensitive materials, has attracted much attention owing to its potential application in the solution of environmental pollution during the past decades. Four doped TiO2systems were constructed and studied by using the first principle based Density Functional Theory .The results indicate that P-doped and N-doped TiO2all have better light absorption in the visible light area than pristine TiO2although the band gap of N-doped system reduced less. However, the band gap of F-doped and Cl-doped TiO2increase a little, which causing the absorption to decrease. We suggest from the results that the P atom and N atom are valuable in the modification of TiO2.

Transition-metal doping induces the transition of electronic and magnetic properties in armchair MoS2 nanoribbons

2017 ◽  
Vol 19 (36) ◽  
pp. 24594-24604 ◽  
Author(s):  
Jing Pan ◽  
Rui Wang ◽  
Xiaoyu Zhou ◽  
Jiansheng Zhong ◽  
Xiaoyong Xu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Electronic Structure ◽  
Transition Metal ◽  
Density Functional ◽  
Transition Metal Doping ◽  
Hydrogen Passivation ◽  
Metal Doping ◽  
Functional Theory ◽  
Electronic And Magnetic Properties

The electronic structure, magnetic properties and stability of transition-metal (TM) doped armchair MoS2 nanoribbons (AMoS2NRs) with full hydrogen passivation have been investigated using density functional theory.

Graphene sheet with periodic vacancy: A first principles study

2021 ◽  
Author(s):  
Deepti Maikhuri ◽  
Jaiparkash Jaiparkash ◽  
Haider Abbas
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Electronic Structure ◽  
Band Gap ◽  
Graphene Sheet ◽  
First Principles ◽  
Density Functional ◽  
Computational Analysis ◽  
Functional Theory ◽  
First Principles Study

Abstract We present a comprehensive first-principles study of the electronic structure of graphene sheet with periodic vacancy. We report the structural, electronic, and magnetic properties of the graphene sheet with periodic vacancy that possess 48 C & 28 H atoms. Computational analysis based on density functional theory predicts that the periodic vacancy can modulate the properties of graphene sheet. Results show that periodic vacancies lead to the manipulation of band gap & could be utilized to tailor the electronic properties of the sheet. Also, it is found that, the graphene sheet with periodic vacancy is non-magnetic in nature.

scholarly journals A High-Throughput Study of the Electronic Structure and Physical Properties of Short-Period (GaAs)m(AlAs)n (m, n ≤ 10) Superlattices Based on Density Functional Theory Calculations

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 709 ◽  
Author(s):  
Qing-Lu Liu ◽  
Zong-Yan Zhao ◽  
Jian-Hong Yi ◽  
Zi-Yang Zhang
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Physical Properties ◽  
Band Gap ◽  
High Throughput ◽  
Density Functional ◽  
Functional Materials ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
High Throughput Study

As important functional materials, the electronic structure and physical properties of (GaAs)m(AlAs)n superlattices (SLs) have been extensively studied. However, due to limitations of computational methods and computational resources, it is sometimes difficult to thoroughly understand how and why the modification of their structural parameters affects their electronic structure and physical properties. In this article, a high-throughput study based on density functional theory calculations has been carried out to obtain detailed information and to further provide the underlying intrinsic mechanisms. The band gap variations of (GaAs)m(AlAs)n superlattices have been systematically investigated and summarized. They are very consistent with the available reported experimental measurements. Furthermore, the direct-to-indirect-gap transition of (GaAs)m(AlAs)n superlattices has been predicted and explained. For certain thicknesses of the GaAs well (m), the band gap value of (GaAs)m(AlAs)n SLs exponentially increases (increasing n), while for certain thicknesses of the AlAs barrier (n), the band gap value of (GaAs)m(AlAs)n SLs exponentially decreases (increasing m). In both cases, the band gap values converge to certain values. Furthermore, owing to the energy eigenvalues at different k-points showing different variation trends, (GaAs)m(AlAs)n SLs transform from a Γ-Γ direct band gap to Γ-M indirect band gap when the AlAs barrier is thick enough. The intrinsic reason for these variations is that the contributions and positions of the electronic states of the GaAs well and the AlAs barrier change under altered thickness conditions. Moreover, we have found that the binding energy can be used as a detector to estimate the band gap value in the design of (GaAs)m(AlAs)n devices. Our findings are useful for the design of novel (GaAs)m(AlAs)n superlattices-based optoelectronic devices.

scholarly journals Hydration activity, crystal structural, and electronic properties studies of Ba-doped dicalcium silicate

2020 ◽  
Vol 9 (1) ◽  
pp. 1027-1033
Author(s):  
Lin Chi ◽  
Ailian Zhang ◽  
Zedong Qiu ◽  
Linchun Zhang ◽  
Zheng Wang ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Density Functional ◽  
Dicalcium Silicate ◽  
Crystallographic Structure ◽  
Crystal Formation ◽  
First Principle ◽  
Functional Theory ◽  
Hydration Rate ◽  
Belite Cement

AbstractHigh belite cement has a wide application potential due to its low energy consumption, low CO2 emission, and excellent durability performance. Due to the low hydration rate and strength development at an early age, the activation of beta-dicalcium silicate (β-C2S) crystallographic structure is essential to improve the early strength of high belite cement. In this study, the β-C2S phase is activated by dissolving Ba2+ ions into the crystal lattice to improve the hydration rate. Unlike the traditional analysis methods of thermodynamics and dynamics theory, the first principle and density functional theory were applied to study the effect of Ba2+ ions on the activation of β-C2S, especially on the crystallographic structure, lattice parameters, and electronic structure change. The crystallographic structure of β-C2S can be activated by doping Ba atom and the crystal formation energy increases and the bandgap between VBM and CBM become narrow in the activated β-C2S crystallographic structure. Comparing the Ca2+ substitution in [CaO6] or [CaO8], the lattice deformation and hydraulic reactivity is more significant in Ba2-C2S and Ba22-C2S. The first principle and density functional theory explains the change of the electronic structure of the activated crystallographic structure and provides a theoretical basis for the purposeful design of material structures.

scholarly journals Effect of Beryllium and Magnesium Doped Stanene Single Layer on Structural and Electronic Properties Using Density Functional Theory as Implemented in Quantum ESPRESSO

2021 ◽  
Author(s):  
Alhassan Shuaibu ◽  
Yakubu Tanko ◽  
Zainab Abdurrahman ◽  
Abdullahi Lawal ◽  
Maharaz Nasir
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Fermi Level ◽  
Band Gap ◽  
Density Functional ◽  
Energy Gap ◽  
Single Layer ◽  
Quantum Spin ◽  
Band Edge ◽  
Functional Theory

Stanene is a quantum spin hall insulator and a favourable material for electronic and optoelectronic devices. Density functional theory (DFT) calculations are performed to study the band gap opening in stanene by investigating the effect of beryllium and magnesium doped stanene single layer to study the electronic and structural properties in stanene. The electronic band energy of pure stanene without spin orbit coupling (SOC) appear to show no energy gap at the Fermi level showing that stanene is a gapless material with Dirac cones at the K point and the band gap opens by a gap of 0.08 eV is opened at the K point. The electronic structure of Be and Mg doped stanene shows that the Fermi level is shifted towards the valance band edge when compared to pure stanene. We have considered 6.25, 12.5, 18.75 and 25% of both Be and mg doping. The electronic structure of Be doped stanene show that the Fermi level is shifted towards the valance band edge when compared to pure stanene. The Dirac point of stanene locates at Γ shifted by 0.38 and 0.51eV for 6.25 and 12.5 %, an energy band gap of 0.27 and 0.50 eV were obtained above the Fermi level for 6.25 and 12.5% respectively. In the case of Mg, the bandgap remains slightly above the Fermi-level and amounts to 0.34 eV for 6.25 % and 0.43eV for 12.5 %, in the case of 18.75 and 25 % the Dirac cone disappear completely, an energy gap of 0.28 eV and 0.60 eV were obtained above the Fermi level for 6.25 and 12.5% respectively, our findings show that the band gap of stanene open at 12.5% doping concentration of both Be and Mg impurities. These obtained band-gap value seem to be sufficient for use of alkaline earth metal doped stanene in optoelectronic and such applications where stanene is incapacitate for its use to switch on/off devices.

Band gap and electronic structure of MgSiN2determined using soft X-ray spectroscopy and density functional theory

2015 ◽  
Vol 9 (4) ◽  
pp. 250-254 ◽  
Author(s):  
Tristan de Boer ◽  
Teak D. Boyko ◽  
Cordula Braun ◽  
Wolfgang Schnick ◽  
Alexander Moewes
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Band Gap ◽  
Density Functional ◽  
Functional Theory ◽  
X Ray

scholarly journals Investigation on the electronic structure, optical, elastic, mechanical, thermodynamic and thermoelectric properties of wide band gap semiconductor double perovskite Ba2InTaO6

RSC Advances ◽  
2019 ◽  
Vol 9 (17) ◽  
pp. 9522-9532 ◽  
Author(s):  
Sajad Ahmad Dar ◽  
Ramesh Sharma ◽  
Vipul Srivastava ◽  
Umesh Kumar Sakalle
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Band Gap ◽  
Thermoelectric Properties ◽  
Density Functional ◽  
Double Perovskite ◽  
Wide Band ◽  
Wide Band Gap ◽  
Functional Theory

In the present paper, double perovskite Ba2InTaO6 was investigated in terms of its structural, electronic, optical, elastic, mechanical, thermodynamic and thermoelectric properties using density-functional theory (DFT).

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