Band gap engineering of bulk and nanosheet SnO: an insight into the interlayer Sn–Sn lone pair interactions

2015 ◽  
Vol 17 (27) ◽  
pp. 17816-17820 ◽  
Author(s):  
Wei Zhou ◽  
Naoto Umezawa
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Band Gap ◽  
Density Functional ◽  
Lone Pair ◽  
Functional Theory ◽  
Band Gap Engineering ◽  
Lone Pair Interactions ◽  
Insight Into ◽  
Pair Interactions

The effects of interlayer lone-pair interactions on the electronic structure of SnO are explored using density-functional theory.

scholarly journals DFT Study of the Electronic Structure of Cubic-SiC Nanopores with a C-Terminated Surface

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
M. Calvino ◽  
A. Trejo ◽  
M. I. Iturrios ◽  
M. C. Crisóstomo ◽  
Eliel Carvajal ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Band Gap ◽  
Density Functional ◽  
Surface Passivation ◽  
Phase Changes ◽  
Surface Relaxation ◽  
Oh Radicals ◽  
Functional Theory ◽  
Band Gap Engineering ◽  
Chemical Surface

A study of the dependence of the electronic structure and energetic stability on the chemical surface passivation of cubic porous silicon carbide (pSiC) was performed using density functional theory (DFT) and the supercell technique. The pores were modeled by removing atoms in the [001] direction to produce a surface chemistry composed of only carbon atoms (C-phase). Changes in the electronic states of the porous structures were studied by using different passivation schemes: one with hydrogen (H) atoms and the others gradually replacing pairs of H atoms with oxygen (O) atoms, fluorine (F) atoms, and hydroxide (OH) radicals. The results indicate that the band gap behavior of the C-phase pSiC depends on the number of passivation agents (other than H) per supercell. The band gap decreased with an increasing number of F, O, or OH radical groups. Furthermore, the influence of the passivation of the pSiC on its surface relaxation and the differences in such parameters as bond lengths, bond angles, and cell volume are compared between all surfaces. The results indicate the possibility of nanostructure band gap engineering based on SiC via surface passivation agents.

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.

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.

DFT insight into axial ligand effects on electronic structure and mechanistic reactivity of oxoiron(iv) porphyrin

2020 ◽  
Vol 22 (21) ◽  
pp. 12173-12179
Author(s):  
Zhifeng Ma ◽  
Naoki Nakatani ◽  
Hiroshi Fujii ◽  
Masahiko Hada
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Axial Ligand ◽  
Functional Theory ◽  
Ligand Effects ◽  
Insight Into

The nature of axial ligand effects is revealed by density functional theory calculations, the ability of axial ligand bound to iron is strong, and the reaction is more reactive.

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.

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