scholarly journals The Interaction of Hydrogen with the van der Waals Crystal γ-InSe

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2526 ◽  
Author(s):  
James Felton ◽  
Elena Blundo ◽  
Sanliang Ling ◽  
Joseph Glover ◽  
Zakhar R. Kudrynskyi ◽  
...  
Keyword(s):  
Density Functional ◽  
Room Temperature ◽  
Theoretical Study ◽  
Van Der Waals ◽  
Transition Metal Dichalcogenides ◽  
Ion Source ◽  
Vibrational Modes ◽  
Functional Theory ◽  
Metal Dichalcogenides ◽  
Experimental And Theoretical Studies

The emergence of the hydrogen economy requires development in the storage, generation and sensing of hydrogen. The indium selenide ( γ -InSe) van der Waals (vdW) crystal shows promise for technologies in all three of these areas. For these applications to be realised, the fundamental interactions of InSe with hydrogen must be understood. Here, we present a comprehensive experimental and theoretical study on the interaction of γ -InSe with hydrogen. It is shown that hydrogenation of γ -InSe by a Kaufman ion source results in a marked quenching of the room temperature photoluminescence signal and a modification of the vibrational modes of γ -InSe, which are modelled by density functional theory simulations. Our experimental and theoretical studies indicate that hydrogen is incorporated into the crystal preferentially in its atomic form. This behaviour is qualitatively different from that observed in other vdW crystals, such as transition metal dichalcogenides, where molecular hydrogen is intercalated in the vdW gaps of the crystal, leading to the formation of “bubbles” for hydrogen storage.

Rational Design of Monolayer Transition Metal Dichalcogenide@Fullerene van der Waals Photovoltaic Heterojunctions with the Aid of Time-Domain Density Functional Theory Simulations

2021 ◽  
Author(s):  
Hong-Jun Zhou ◽  
Dong-Hui Xu ◽  
Qin-Hong Yang ◽  
Xiangyang Liu ◽  
Ganglong Cui ◽  
...  
Keyword(s):  
Transition Metal ◽  
Time Domain ◽  
Density Functional ◽  
Rational Design ◽  
Van Der Waals ◽  
Transition Metal Dichalcogenides ◽  
Transition Metal Dichalcogenide ◽  
Photovoltaic Devices ◽  
Functional Theory ◽  
Metal Dichalcogenides

Van der Waals heterojunctions formed by transition metal dichalcogenides (TMDs) and fullerenes are promising candidates for novel photovoltaic devices due to the excellent optoelectronic properties of both TMDs and fullerenes....

Flexoelectricity in atomic monolayers from first principles

Nanoscale ◽  
2020 ◽  
Author(s):  
Shashikant Kumar ◽  
David Codony ◽  
Irene Arias ◽  
Phanish Suryanarayana
Keyword(s):  
Density Functional Theory ◽  
Transition Metal ◽  
Ab Initio ◽  
First Principles ◽  
Density Functional ◽  
Transition Metal Dichalcogenides ◽  
Functional Theory ◽  
Group Iii ◽  
Flexoelectric Effect ◽  
Metal Dichalcogenides

We study the flexoelectric effect in fifty-four select atomic monolayers using ab initio Density Functional Theory (DFT). Specifically, considering representative materials from each of Group III monochalcogenides, transition metal dichalcogenides...

scholarly journals Study of Structural and Electronic Properties of Intercalated Transition Metal Dichalcogenides Compound MTiS2 (M = Cr, Mn, Fe) by Density Functional Theory

2021 ◽  
Keyword(s):  
Transition Metal ◽  
Band Structure ◽  
Electronic Properties ◽  
Density Of States ◽  
Density Functional ◽  
Transition Metal Dichalcogenides ◽  
Energy Band Structure ◽  
Functional Theory ◽  
Structural And Electronic Properties ◽  
Metal Dichalcogenides

In the present work, we have studied intercalated Transition Metal Dichalcogenides (TMDC) MTiS2 compounds (M = Cr, Mn, Fe) by Density Functional Theory (DFT) with Generalized Gradient Approximation (GGA). We have computed the structural and electronic properties by using first principle method in QUANTUM ESPRESSO computational code with an ultra-soft pseudopotential. A guest 3d transition metal M (viz; Cr, Mn, Fe) can be easily intercalated in pure transition metal dichalcogenides compound like TiS2. In the present work, the structural optimization, electronic properties like the energy band structure, density of states (DoS), partial or projected density of states (PDoS) and total density of states (TDoS) are reported. The energy band structure of MTiS2 compound has been found overlapping energy bands in the Fermi region. We conclude that the TiS2 intercalated compound has a small band gap while the doped compound with guest 3d-atom has metallic behavior as shown form its overlapped band structure.

Metal Dichalcogenide Nanomeshes: Structural, Electronic and Magnetic Properties

2021 ◽  
Author(s):  
Mohamed Helal ◽  
H. M. El-Sayed ◽  
Ahmed A Maarouf ◽  
Mohamed Fadlallah
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Transition Metal ◽  
Structural Stability ◽  
Density Functional ◽  
Transition Metal Dichalcogenides ◽  
Two Dimensional ◽  
Functional Theory ◽  
Electronic And Magnetic Properties ◽  
Metal Dichalcogenides

Motivated by the successful preparation of two-dimensional transition metal dichalcogenides (2D- TMDs) nanomeshes in the last three years, we use density functional theory (DFT) to study the structural stability, mechanical,...

scholarly journals Strain-induced effects on the electronic properties of 2D materials

2020 ◽  
Vol 10 ◽  
pp. 184798042090256 ◽  
Author(s):  
Sara Postorino ◽  
Davide Grassano ◽  
Marco D’Alessandro ◽  
Andrea Pianetti ◽  
Olivia Pulci ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
2D Materials ◽  
Transition Metal Dichalcogenides ◽  
Many Body ◽  
Functional Theory ◽  
Metal Dichalcogenides ◽  
Extreme Sensitivity ◽  
Nonuniform Strain

Thanks to the ultrahigh flexibility of 2D materials and to their extreme sensitivity to applied strain, there is currently a strong interest in studying and understanding how their electronic properties can be modulated by applying a uniform or nonuniform strain. In this work, using density functional theory (DFT) calculations, we discuss how uniform biaxial strain affects the electronic properties, such as ionization potential, electron affinity, electronic gap, and work function, of different classes of 2D materials from X-enes to nitrides and transition metal dichalcogenides. The analysis of the states in terms of atomic orbitals allows to explain the observed trends and to highlight similarities and differences among the various materials. Moreover, the role of many-body effects on the predicted electronic properties is discussed in one of the studied systems. We show that the trends with strain, calculated at the GW level of approximation, are qualitatively similar to the DFT ones solely when there is no change in the character of the valence and conduction states near the gap.

scholarly journals Synthesis of Pyrazolo-Fused 4-Azafluorenones in an Ionic Liquid. Mechanistic Insights by Joint Studies Using DFT Analysis and Mass Spectrometry

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 820
Author(s):  
Efraín Polo ◽  
Valentina Arce-Parada ◽  
Xaviera A. López-Cortés ◽  
Jesús Sánchez-Márquez ◽  
Alejandro Morales-Bayuelo ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Density Functional ◽  
Room Temperature ◽  
Theoretical Study ◽  
Environmentally Benign ◽  
Reaction Conditions ◽  
Conceptual Density Functional Theory ◽  
Functional Theory ◽  
Three Component Reaction ◽  
Work Up

A series of pyrazolo-fused 4-azafluorenones (indeno[1,2-b]pyrazolo[4,3-e]pyridines, IPP) were synthesized via the three-component reaction between arylaldehydes, 3-methyl-1H-pyrazol-5-amine and 1,3-indanedione in an ionic liquid as a catalyst at room temperature. The applied synthetic route has the advantages of easy work-up under mild reaction conditions presenting moderate yields and an environmentally benign procedure. A theoretical study based on conceptual-density functional theory has been done, bond reactivity indices have been calculated and an electrophilic and nucleophilic character of localized orbitals has been determined to analyze the possible electronic mechanisms.

Excitons in two-dimensional atomic layer materials from time-dependent density functional theory: mono-layer and bi-layer hexagonal boron nitride and transition-metal dichalcogenides

2020 ◽  
Vol 22 (5) ◽  
pp. 2908-2916 ◽  
Author(s):  
Yasumitsu Suzuki ◽  
Kazuyuki Watanabe
Keyword(s):  
Density Functional ◽  
Hexagonal Boron Nitride ◽  
Transition Metal Dichalcogenides ◽  
Atomic Layer ◽  
Time Dependent ◽  
Two Dimensional ◽  
Functional Theory ◽  
Mono Layer ◽  
Metal Dichalcogenides ◽  
Dependent Density

Time-dependent density functional theory has been applied to the calculation of absorption spectra for two dimensional atomic layer materials: mono-layer and bi-layer hexagonal boron nitride and mono-layer transition metal dichalcogenides.

scholarly journals On the forbidden graphene’s ZO (out-of-plane optic) phononic band-analog vibrational modes in fullerenes

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jesús N. Pedroza-Montero ◽  
Ignacio L. Garzón ◽  
Huziel E. Sauceda
Keyword(s):  
High Frequency ◽  
Density Functional ◽  
Room Temperature ◽  
Bulk Material ◽  
Characteristic Line ◽  
Vibrational Modes ◽  
Frequency Range ◽  
Functional Theory ◽  
Phonon Band ◽  
Out Of Plane

AbstractThe study of nanostructures’ vibrational properties is at the core of nanoscience research. They are known to represent a fingerprint of the system as well as to hint the underlying nature of chemical bonds. In this work, we focus on addressing how the vibrational density of states (VDOS) of the carbon fullerene family (Cn: n = 20 → 720 atoms) evolves from the molecular to the bulk material (graphene) behavior using density functional theory. We find that the fullerene’s VDOS smoothly converges to the graphene characteristic line-shape, with the only noticeable discrepancy in the frequency range of the out-of-plane optic (ZO) phonon band. From a comparison of both systems we obtain as main results that: (1) The pentagonal faces in the fullerenes impede the existence of the analog of the high frequency graphene’s ZO phonons, (2) which in the context of phonons could be interpreted as a compression (by 43%) of the ZO phonon band by decreasing its maximum allowed radial-optic vibration frequency. And 3) as a result, the deviation of fullerene’s VDOS relative to graphene may hold important thermodynamical implications, such as larger heat capacities compared to graphene at room-temperature. These results provide insights that can be extrapolated to other nanostructures containing pentagonal rings or pentagonal defects.

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