scholarly journals DFT calculations of the structure and stability of copper clusters on MoS2

2020 ◽  
Vol 11 ◽  
pp. 391-406
Author(s):  
Cara-Lena Nies ◽  
Michael Nolan

Layered materials, such as MoS2, are being intensely studied due to their interesting properties and wide variety of potential applications. These materials are also interesting as supports for low-dimensional metals for catalysis, while recent work has shown increased interest in using 2D materials in the electronics industry as a Cu diffusion barrier in semiconductor device interconnects. The interaction between different metal structures and MoS2 monolayers is therefore of significant importance and first-principles simulations can probe aspects of this interaction not easily accessible to experiment. Previous theoretical studies have focused particularly on the adsorption of a range of metallic elements, including first-row transition metals, as well as Ag and Au. However, most studies have examined single-atom adsorption or adsorbed nanoparticles of noble metals. This means there is a knowledge gap in terms of thin film nucleation on 2D materials. To begin addressing this issue, we present in this paper a first-principles density functional theory (DFT) study of the adsorption of small Cu n (n = 1–4) structures on 2D MoS2 as a model system. We find on a perfect MoS2 monolayer that a single Cu atom prefers an adsorption site above the Mo atom. With increasing nanocluster size the nanocluster binds more strongly when Cu atoms adsorb atop the S atoms. Stability is driven by the number of Cu–Cu interactions and the distance between adsorption sites, with no obvious preference towards 2D or 3D structures. The introduction of a single S vacancy in the monolayer enhances the copper binding energy, although some Cu n nanoclusters are actually unstable. The effect of the vacancy is localised around the vacancy site. Finally, on both the pristine and the defective MoS2 monolayer, the density-of-states analysis shows that the adsorption of Cu introduces new electronic states as a result of partial Cu oxidation, but the metallic character of Cu nanoclusters is preserved.

2019 ◽  
Author(s):  
Cara-Lena Nies ◽  
Michael Nolan

<div>Layered materials, such as MoS2, are being intensely studied due to their interesting properties and wide variety of potential applications. These materials are also interesting as supports for low dimensional metals for catalysis, while recent work has shown increased interest in using 2D materials in the electronics industry as a Cu diffusion barrier in semiconductor device interconnects. The interaction between different metal structures and MoS2 monolayers is therefore of significant importance and first principle simulations can probe aspects of this interaction not easily accessible to experiment. Previous theoretical studies have focused particularly on the adsorption of a range of metallic elements, including first row transition metals, as well as Ag and Au. However, most studies have examined single atom adsorption or adsorb nanoparticles of noble metals. This means there is a knowledge gap in terms of thin film nucleation on 2D materials. To begin addressing this issue, we present in this paper a first principles density functional theory (DFT) study of the adsorption of small Cu_n structures, where n = 1-4, on 2D MoS2 as a model system. We find on a perfect MoS2 monolayer that a single Cu atom prefers an adsorption site above the Mo atom. With increasing nanocluster size the nanocluster binds more strongly when Cu atoms adsorb atop the S atom. Stability is driven by the number of Cu-Cu interactions and the distance between adsorption sites, with no obvious preference towards 2D or 3D structures. The introduction of a single S vacancy in the monolayer enhances copper binding energy, although some Cu_n nanoclusters are actually unstable. The effect of the vacancy is localised around the vacancy site. Finally on both the pristine and defective MoS2 monolayer, the density of states analysis shows that the adsorption of Cu introduces new electronic states as a result of partial Cu oxidation, but the metallic character of Cu nanoclusters is preserved. </div><div><br></div>


2019 ◽  
Author(s):  
Cara-Lena Nies ◽  
Michael Nolan

<div>Layered materials, such as MoS2, are being intensely studied due to their interesting properties and wide variety of potential applications. These materials are also interesting as supports for low dimensional metals for catalysis, while recent work has shown increased interest in using 2D materials in the electronics industry as a Cu diffusion barrier in semiconductor device interconnects. The interaction between different metal structures and MoS2 monolayers is therefore of significant importance and first principle simulations can probe aspects of this interaction not easily accessible to experiment. Previous theoretical studies have focused particularly on the adsorption of a range of metallic elements, including first row transition metals, as well as Ag and Au. However, most studies have examined single atom adsorption or adsorb nanoparticles of noble metals. This means there is a knowledge gap in terms of thin film nucleation on 2D materials. To begin addressing this issue, we present in this paper a first principles density functional theory (DFT) study of the adsorption of small Cu_n structures, where n = 1-4, on 2D MoS2 as a model system. We find on a perfect MoS2 monolayer that a single Cu atom prefers an adsorption site above the Mo atom. With increasing nanocluster size the nanocluster binds more strongly when Cu atoms adsorb atop the S atom. Stability is driven by the number of Cu-Cu interactions and the distance between adsorption sites, with no obvious preference towards 2D or 3D structures. The introduction of a single S vacancy in the monolayer enhances copper binding energy, although some Cu_n nanoclusters are actually unstable. The effect of the vacancy is localised around the vacancy site. Finally on both the pristine and defective MoS2 monolayer, the density of states analysis shows that the adsorption of Cu introduces new electronic states as a result of partial Cu oxidation, but the metallic character of Cu nanoclusters is preserved. </div><div><br></div>


Author(s):  
Hui Wang ◽  
Chen Pan ◽  
Sheng-Yan Wang ◽  
Hong Jiang ◽  
Yin-Chang Zhao ◽  
...  

Using first-principles calculations based on density functional perturbation theory, we demonstrate hydrogenation-induced superconductivity in monolayer TiB2H. Hydrogen adatoms destroy the Dirac state of monolayer TiB2 and monolayer TiB2H has a high vibration frequency. Monolayer TiB2H is a phonon-mediated superconductor. Monolayer TiB2H has a predicted [Formula: see text] of 8[Formula: see text]K, which further increases under external tensile strain. Thus, this study extends our understanding of superconductivity in two-dimensional (2D) materials and its potential applications.


MRS Advances ◽  
2019 ◽  
Vol 4 (50) ◽  
pp. 2699-2707
Author(s):  
V. W. Elloh ◽  
Soni Mishra ◽  
A. Yaya ◽  
Abhishek Kumar Mishra

AbstractLayered zirconium hydrogen phosphate intercalation compounds can be easily tuned, leading to potential applications in many fields, specifically by introducing them in different polymeric composites as nanofillers. Employing first-principles density functional theory based calculations, we have investigated ground state electronic structure properties of α-zirconium hydrogen phosphate (α-ZrP). We discuss the structure and electronic band structure, where projected density of states calculations have been discussed to understand the different atomic orbitals contributions to electronic bands. ZrP has numerous properties of interest for use in many semiconductor device structures, specifically, layered zirconium hydrogen phosphate has substantial promise for both optical devices and for high power electronics due to its large direct band gap. Our structural calculations suggest that layered zirconium hydrogen phosphate exhibits monoclinic structure. The calculated structural parameters and band gap are in good agreement with available experimental data.


2021 ◽  
Author(s):  
Lanjuan Zhou ◽  
Sujing Yu ◽  
Yan Yang ◽  
Qi Li ◽  
Tingting Li ◽  
...  

In this paper, the effects of five noble metals (Au, Pt, Pd, Ag, Ru) doped MoSe2 on improving gas sensing performance were predicted through density functional theory (DFT) based on...


Author(s):  
Mohammad Zafari ◽  
Arun S. Nissimagoudar ◽  
Muhammad Umer ◽  
Geunsik Lee ◽  
Kwang S. Kim

The catalytic activity and selectivity can be improved for nitrogen fixation by using hollow sites and vacancy defects in 2D materials, while a new machine learning descriptor accelerates screening of efficient electrocatalysts.


2011 ◽  
Vol 311-313 ◽  
pp. 526-529
Author(s):  
Cai Juan Xia ◽  
Han Chen Liu ◽  
Ji Xin Yin

Using non-equilibrium Green’s function formalism combined with first-principles density functional theory, we investigate the electronic transport properties of a triangle terarylene(open- and closed-ring forms) optical molecular switch. The influence of the HOMO-LUMO gaps and the spatial distributions of molecular orbitals on the quantum transport through the molecular device is discussed. Theoretical results show that the conductance of the closed-ring is 3-8 times larger than that of open-ring, which expect that this system can be one of good candidates for optical switches due to this unique advantage, and may have some potential applications in future molecular circuit.


Author(s):  
Amina Bouheddadj ◽  
Tarik Ouahrani ◽  
Gbèdodé Wilfried KANNHOUNON ◽  
Boufatah Reda ◽  
Sumeya Bedrane ◽  
...  

First-principles based on density functional theory (DFT) calculations were performed to investigate the interaction of two-dimensional (2D) HfS2 with SO2, a harmful gas with implications for climate change. In particular,...


Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 94
Author(s):  
Mailing Berwanger ◽  
Rajeev Ahuja ◽  
Paulo Cesar Piquini

First principles density functional theory was used to study the energetic, structural, and electronic properties of HfS 2 and TiS 2 materials in their bulk, pristine monolayer, as well as in the monolayer structure with the adsorbed C, N, and P atoms. It is shown that the HfS 2 monolayer remains a semiconductor while TiS 2 changes from semiconductor to metallic behavior after the atomic adsorption. The interaction with the external atoms introduces localized levels inside the band gap of the pristine monolayers, significantly altering their electronic properties, with important consequences on the practical use of these materials in real devices. These results emphasize the importance of considering the interaction of these 2D materials with common external atomic or molecular species.


2019 ◽  
Vol 33 (04) ◽  
pp. 1950044 ◽  
Author(s):  
X. Jia ◽  
L. An

The first-principles method based on density functional theory has been used to investigate the adsorption performance of NO/NO2 molecules on intrinsic, Ag-doped, Pt-doped and Au-doped graphene. Results show that graphene doped with Ag/Pt/Au has shorter final adsorption distance, larger adsorption energy and charge transfer amount with NO/NO2 molecules than intrinsic graphene, and the charge densities of doped graphene and NO/NO2 molecules overlap effectively. Therefore, doping graphene with noble metals can greatly enhance the adsorption between graphene and NO/NO2 molecules. Analysis also reveals that Au-doped graphene has the strongest adsorption effect on NO/NO2 molecules, followed by Ag-doped graphene, while Pt-doped graphene has the weakest role on the adsorption of NO/NO2 molecules. The work conducted in this research provides a theoretical guidance for the application of NO/NO2 gas sensors based on graphene.


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