Band gap and effective mass of multilayer BN/graphene/BN: van der Waals density functional approach

2014 ◽  
Vol 115 (19) ◽  
pp. 194304 ◽  
Author(s):  
Arqum Hashmi ◽  
Jisang Hong
Keyword(s):  
Band Gap ◽  
Effective Mass ◽  
Density Functional ◽  
Van Der Waals ◽  
Functional Approach

Efficient Prediction of Structural and Electronic Properties of Hybrid 2D Materials Using DFT and Machine Learning

2018 ◽  
Author(s):  
Sherif Tawfik ◽  
Olexandr Isayev ◽  
Catherine Stampfl ◽  
Joseph Shapter ◽  
David Winkler ◽  
...  
Keyword(s):  
Machine Learning ◽  
Band Gap ◽  
Density Functional ◽  
2D Materials ◽  
Van Der Waals ◽  
Building Blocks ◽  
Machine Learning Techniques ◽  
Interlayer Distance ◽  
Computational Screening ◽  
Wide Range

Materials constructed from different van der Waals two-dimensional (2D) heterostructures offer a wide range of benefits, but these systems have been little studied because of their experimental and computational complextiy, and because of the very large number of possible combinations of 2D building blocks. The simulation of the interface between two different 2D materials is computationally challenging due to the lattice mismatch problem, which sometimes necessitates the creation of very large simulation cells for performing density-functional theory (DFT) calculations. Here we use a combination of DFT, linear regression and machine learning techniques in order to rapidly determine the interlayer distance between two different 2D heterostructures that are stacked in a bilayer heterostructure, as well as the band gap of the bilayer. Our work provides an excellent proof of concept by quickly and accurately predicting a structural property (the interlayer distance) and an electronic property (the band gap) for a large number of hybrid 2D materials. This work paves the way for rapid computational screening of the vast parameter space of van der Waals heterostructures to identify new hybrid materials with useful and interesting properties.

scholarly journals Electric field tunable band-gap crossover in black(blue) phosphorus/g-ZnO van der Waals heterostructures

RSC Advances ◽  
2017 ◽  
Vol 7 (55) ◽  
pp. 34584-34590 ◽  
Author(s):  
Wei Zhang ◽  
Lifa Zhang
Keyword(s):  
Zinc Oxide ◽  
Optical Properties ◽  
Electric Field ◽  
Band Gap ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Van Der Waals ◽  
Van Der Waals Heterostructures ◽  
Hybrid Density Functional ◽  
Tunable Band Gap

Using hybrid density functional calculations, we studied the electronic and optical properties of graphitic zinc oxide (g-ZnO) and phosphorene van der Waals (vdW) heterostructures.

scholarly journals Tunable spin-polarized band gap in Si2/NiI2 vdW heterostructure

RSC Advances ◽  
2020 ◽  
Vol 10 (15) ◽  
pp. 8927-8935 ◽  
Author(s):  
Douglas Duarte de Vargas ◽  
Rogério José Baierle
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Band Gap ◽  
Electronic Properties ◽  
Density Functional ◽  
Van Der Waals ◽  
Functional Theory ◽  
Spin Polarized ◽  
Structural And Electronic Properties ◽  
Vdw Heterostructure

Using density functional theory (DFT) calculations we investigate the structural and electronic properties of a heterogeneous van der Waals (vdW) structure consisting of silicene and NiI2 single layers.

scholarly journals A Reasonable DFT Calculation Method for Hybrid Organic-Inorganic Halide Perovskites

2021 ◽  
Vol 59 (4) ◽  
pp. 256-261
Author(s):  
Jin-Woong Lee ◽  
Woon Bae Park
Keyword(s):  
Band Gap ◽  
Effective Mass ◽  
Density Functional ◽  
Formation Energy ◽  
Dft Calculation ◽  
Initial Orientation ◽  
Model Structure ◽  
Gap Formation ◽  
Treatment Needs ◽  
Input Model

Hybrid Organic-Inorganic Perovskites (HOIP) have received a great deal of attention as a key material for applications like solar cells and light emitting devices because of their many advantages, in spite of their stability and toxicity issues. Attempting to discover and characterize novel HOIPs using just an experimental approach would be prohibitively time-and-cost-consuming. Using theoretical or empirical calculations would greatly help. For these reasons, HOIP has been actively investigated using DFT (Density Functional Theory) calculations, which have significantly reduced research time and cost. However, the input model structure treatment needs to be standardized to avoid unnecessary complications. For this purpose, a sort of optimization of DFT calculation protocols for HOIPs is essential, because DFT calculation results are greatly affected by the input model structure arrangements and exchange-correlation functionals. In this paper, we used DFT to calculate the band gap, formation energy, and effective mass of the well-known cubic perovskite structure, methylammonium lead iodide (CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub>: MAPbI<sub>3</sub>) with and without the van der Waals function and SOC (Spin Orbit Coupling) and various geometrical molecule arrangements in the structure. In particular, the initial orientation of the ‘A’ site molecule in the input model structure was intensively investigated in terms of band gap, formation energy and effective mass. It was found that the relaxation-induced final structure was greatly influenced by the initial orientation of the molecule and thereby significantly affected the DFT-calculated result.

scholarly journals Structural and Electronic Properties of Heterostructures Composed of Antimonene and Monolayer MoS2

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2358
Author(s):  
Congcong Zhou ◽  
Xiaodan Li ◽  
Taotao Hu
Keyword(s):  
Band Gap ◽  
Electronic Properties ◽  
Density Functional ◽  
Van Der Waals ◽  
Broad Band ◽  
Photogenerated Electron ◽  
Band Alignment ◽  
Monolayer Mos2 ◽  
Photoelectric Properties ◽  
Structural And Electronic Properties

Antimonene is found to be a promising material for two-dimensional optoelectronic equipment due to its broad band gap and high carrier mobility. The van der Waals heterostructure, as a unique structural unit for the study of photoelectric properties, has attracted great attention. By using ab initio density functional theory with van der Waals corrections, we theoretically investigated the structural and electronic properties of the heterostructures composed of antimonene and monolayer MoS2. Our results revealed that the Sb/MoS2 hetero-bilayer is an indirect semiconductor with type-II band alignment, which implies the spatial separation of photogenerated electron–hole pairs. Due to the weak van der Waals interlayer interactions between the adjacent sheets of the hetero-bilayer systems, the band structures of isolated antimonene and monolayer MoS2 are preserved. In addition, a tunable band gap in Sb/MoS2 hetero-bilayer can be realized by applying in-plane biaxial compressing/stretching. When antimonene and monolayer MoS2 are stacked into superlattices, the indirect semiconductors turn into direct semiconductors with the decreased band gaps. Our results show that the antimonene-based hybrid structures are good candidate structures for photovoltaic devices.

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