scholarly journals Electronic and Optical Properties of Atomic-Scale Heterostructure Based on MXene and MN (M = Al, Ga): A DFT Investigation

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2236
Author(s):  
Kai Ren ◽  
Ruxin Zheng ◽  
Peng Xu ◽  
Dong Cheng ◽  
Wenyi Huo ◽  
...  
Keyword(s):  
First Principles ◽  
2D Materials ◽  
Absorption Capacity ◽  
Band Alignment ◽  
Atomic Scale ◽  
First Principles Calculation ◽  
Photovoltaic Devices ◽  
Light Emitting ◽  
Type Band ◽  
Alignment Structure

After the discovery of graphene, a lot of research has been conducted on two-dimensional (2D) materials. In order to increase the performance of 2D materials and expand their applications, two different layered materials are usually combined by van der Waals (vdW) interactions to form a heterostructure. In this work, based on first-principles calculation, some charming properties of the heterostructure constructed by Hf2CO2, AlN and GaN are addressed. The results show that Hf2CO2/AlN and Hf2CO2/GaN vdW heterostructures can keep their original band structure shape and have strong thermal stability at 300 K. In addition, the Hf2CO2/MN heterostructure has I-type band alignment structure, which can be used as a promising light-emitting device material. The charge transfer between the Hf2CO2 and AlN (or GaN) monolayers is 0.1513 (or 0.0414) |e|. The potential of Hf2CO2/AlN and Hf2CO2/GaN vdW heterostructures decreases by 6.445 eV and 3.752 eV, respectively, across the interface. Furthermore, both Hf2CO2/AlN and Hf2CO2/GaN heterostructures have remarkable optical absorption capacity, which further shows the application prospect of the Hf2CO2/MN heterostructure. The study of this work provides theoretical guidance for the design of heterostructures for use as photocatalytic and photovoltaic devices.

scholarly journals Band Bending Mechanism in CdO/Arsenene Heterostructure: A Potential Direct Z-scheme Photocatalyst

2021 ◽  
Vol 9 ◽  
Author(s):  
Kai Ren ◽  
Ruxin Zheng ◽  
Jin Yu ◽  
Qingyun Sun ◽  
Jianping Li
Keyword(s):  
First Principles ◽  
2D Materials ◽  
Layered Materials ◽  
Band Alignment ◽  
Type Ii ◽  
Band Bending ◽  
Application Range ◽  
Bending Mechanism ◽  
Vdw Heterostructure ◽  
Vdw Interaction

For the few years, two-dimensional (2D) materials have aroused general focus. In order to expand the properties and application range of 2D materials, two different layered materials are usually combined into heterostructure through van der Waals (vdW) interaction. In this research, based on first-principles simulation, we propose CdO/Arsenene (CdO/As) vdW heterostructure as a semiconductor possessing a direct bandgap by 2.179 eV. Besides, the CdO/As vdW heterostructure presents type-II band alignment, which can be used as a remarkable photocatalyst. Importantly, the CdO/As heterostructure demonstrates a direct Z-type principle photocatalyst by exploring the band bending mechanism in the heterostructure. Furthermore, we calculated the light absorption characteristics of CdO/As vdW heterostructure by optical absorption spectrum and conversion efficiency of a novel solar-to-hydrogen efficiency (ηSTH) about 11.67%, which is much higher than that of other 2D photocatalysts. Our work can provide a theoretical guidance for the designing of Z-scheme photocatalyst.

scholarly journals Ab Initio Calculations for the Electronic, Interfacial and Optical Properties of Two-Dimensional AlN/Zr2CO2 Heterostructure

2021 ◽  
Vol 9 ◽  
Author(s):  
Kai Ren ◽  
Ruxin Zheng ◽  
Junbin Lou ◽  
Jin Yu ◽  
Qingyun Sun ◽  
...  
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
2D Materials ◽  
Type I ◽  
Two Dimensional ◽  
Visible Light Region ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Light Region ◽  
Vdw Heterostructure

Recently, expanding the applications of two-dimensional (2D) materials by constructing van der Waals (vdW) heterostructures has become very popular. In this work, the structural, electronic and optical absorption performances of the heterostructure based on AlN and Zr2CO2 monolayers are studied by first-principles simulation. It is found that AlN/Zr2CO2 heterostructure is a semiconductor with a band gap of 1.790 eV. In the meanwhile, a type-I band structure is constructed in AlN/Zr2CO2 heterostructure, which can provide a potential application of light emitting devices. The electron transfer between AlN and Zr2CO2 monolayer is calculated as 0.1603 |e| in the heterostructure, and the potential of AlN/Zr2CO2 heterostructure decreased by 0.663 eV from AlN layer to Zr2CO2 layer. Beisdes, the AlN/Zr2CO2 vdW heterostructure possesses excellent light absorption ability of in visible light region. Our research provides a theoretical guidance for the designing of advanced functional heterostructures.

scholarly journals Atomic-Scale Superlubricity in Ti2CO2@MoS2 Layered Heterojunctions Interface: A First Principles Calculation Study

ACS Omega ◽  
2021 ◽  
Vol 6 (13) ◽  
pp. 9013-9019
Author(s):  
Youwei Zhang ◽  
Xingzhu Chen ◽  
Arramel ◽  
Kwaw Blankson Augustine ◽  
Peng Zhang ◽  
...  
Keyword(s):  
First Principles ◽  
Atomic Scale ◽  
First Principles Calculation

First-principles Calculation of Electron Mobilities in Ultrathin SOI MOSFETs

2004 ◽  
Vol 829 ◽  
Author(s):  
Matthew H. Evans ◽  
Xiaoguang Zhang ◽  
John D. Joannopoulos ◽  
Sokrates T. Pantelides
Keyword(s):  
Electron Transport ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Computational Effort ◽  
Silicon On Insulator ◽  
Atomic Scale ◽  
First Principles Calculation ◽  
Oxide Interface ◽  
Ultrathin Soi

ABSTRACTUltrathin silicon-on-insulator (UTSOI) technology1 has emerged as a key candidate for sub-100nm gate length CMOS devices. Recent experiments have characterized MOSFETs with silicon channels as thin as 1nm (four atomic layers of silicon),2,3 and found them to be well-behaved electrically. Quantum effects are important to the electron transport in such devices, and the penetration of the electron wavefunction into the gate oxide introduces new scattering mechanisms. We introduce here a novel method for first-principles calculation of electron mobilities in ultrathin SOI channels, including surface roughness and defect scattering. The electronic structure and scattering potentials are calculated with Density Functional Theory in the Local Density Approximation (DFT-LDA), and the mobility is calculated through Green's functions. The method requires little computational effort beyond that of the DFT-LDA calculations, and allows the calculation of temperature- and carrier concentration-dependent mobilities. Since the silicon-oxide interface is treated at the atomic-scale, the mobility contributions of different defects (e.g. suboxide bonds, oxide protrusions) and impurities (e.g. nitrogen, hydrogen) can be calculated separately, giving a precise physical picture of channel electron transport.

Effects of adatom and gas molecule adsorption on the physical properties of tellurene: a first principles investigation

2018 ◽  
Vol 20 (6) ◽  
pp. 4058-4066 ◽  
Author(s):  
Xiao Hua Wang ◽  
Da Wei Wang ◽  
Ai Jun Yang ◽  
Nikhil Koratkar ◽  
Ji Feng Chu ◽  
...  
Keyword(s):  
Physical Properties ◽  
Experimental Work ◽  
First Principles ◽  
2D Materials ◽  
First Principles Calculation ◽  
Two Dimensional ◽  
Molecule Adsorption ◽  
Gas Molecule

Tellurene is a new member of the two-dimensional (2D) materials’ family, whose existence has been recently confirmed by first principles calculation and experimental work.

scholarly journals Corrosion Resistance of Ultrathin Two-Dimensional Coatings: First-Principles Calculations towards In-Depth Mechanism Understanding and Precise Material Design

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2011
Author(s):  
Tian-Yu Sun ◽  
Yu Hao ◽  
Ying-Hao Wu ◽  
Wen-Jie Zhao ◽  
Liang-Feng Huang
Keyword(s):  
Corrosion Resistance ◽  
First Principles ◽  
Density Functional ◽  
Hexagonal Boron Nitride ◽  
Material Design ◽  
Atomic Scale ◽  
First Principles Calculation ◽  
Kinetic Properties ◽  
Two Dimensional ◽  
Anticorrosion Performance

In recent years, ultrathin two-dimensional (2D) coatings, e.g., graphene (Gr) and hexagonal boron nitride (h-BN), are intriguing research foci in the field of anticorrosion because their high air stability, excellent impermeability, high optical transparency, and atomistic thickness have endowed them with attractive anticorrosion applications. The microstructure of 2D coatings, coating–substrate interactions, and properties of 2D coatings on substrates in a variety of environmental conditions (e.g., at different temperatures, stresses, and pH values) are the key factors governing the anticorrosion performance of 2D coatings and are among the central topics for all 2D-coating studies. For many conventional experimental measurements (e.g., microscopy and electrochemical methods), there exist challenges to acquire detailed information on the atomistic mechanisms for the involved subnanometer scale corrosion problems. Alternatively, as a precise and efficient quantum-mechanical simulation approach, the first-principles calculation based on density-functional theory (DFT) has become a powerful way to study the thermodynamic and kinetic properties of materials on the atomic scale, as well as to clearly reveal the underlying microscopic mechanisms. In this review, we introduce the anticorrosion performance, existing problems, and optimization ways of Gr and h-BN coatings and summarize important recent DFT results on the critical and complex roles of coating defects and coating–substrate interfaces in governing their corrosion resistance. These DFT progresses have shed much light on the optimization ways towards better anticorrosion 2D coatings and also guided us to make a prospect on the further development directions and promising design schemes for superior anticorrosion ultrathin 2D coatings in the future.

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