scholarly journals Structure–Property Relationships in Transition Metal Dichalcogenide Bilayers under Biaxial Strains

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2639
Author(s):  
Pingping Jiang ◽  
Pascal Boulet ◽  
Marie-Christine Record
Keyword(s):  
Density Functional ◽  
Compressive Strain ◽  
Bond Critical Point ◽  
Transition Metal Dichalcogenide ◽  
Structure Property ◽  
Photovoltaic Properties ◽  
Functional Theory ◽  
Leading Role ◽  
Structure Property Relationships

This paper reports a Density Functional Theory (DFT) investigation of the electron density and optoelectronic properties of two-dimensional (2D) MX2 (M = Mo, W and X = S, Se, Te) subjected to biaxial strains. Upon strains ranging from −4% (compressive strain) to +4% (tensile strain), MX2 bilayers keep the same bandgap type but undergo a non-symmetrical evolution of bandgap energies and corresponding effective masses of charge carriers (m*). Despite a consistency regarding the electronic properties of Mo- and WX2 for a given X, the strain-induced bandgap shrinkage and m* lowering are strong enough to alter the strain-free sequence MTe2, MSe2, MS2, thus tailoring the photovoltaic properties, which are found to be direction dependent. Based on the quantum theory of atoms in molecules, the bond degree (BD) at the bond critical points was determined. Under strain, the X-X BD decreases linearly as X atomic number increases. However, the kinetic energy per electron G/ρ at the bond critical point is independent of strains with the lowest values for X = Te, which can be related to the highest polarizability evidenced from the dielectric properties. A cubic relationship between the absolute BD summation of M-X and X-X bonds and the static relative permittivity was observed. The dominant position of X-X bond participating in this cubic relationship in the absence of strain was substantially reinforced in the presence of strain, yielding the leading role of the X-X bond instead of the M-X one in the photovoltaic response of 2D MX2 material.

scholarly journals Structure-Property Relationships of 2D Ga/In Chalcogenides

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2188
Author(s):  
Pingping Jiang ◽  
Pascal Boulet ◽  
Marie-Christine Record
Keyword(s):  
Density Functional ◽  
Lattice Mismatch ◽  
Decisive Role ◽  
Interatomic Interaction ◽  
Structure Property ◽  
Functional Theory ◽  
Structure Property Relationships ◽  
Structure Property Relationship ◽  
Maximum Conversion Efficiency

Two-dimensional MX (M = Ga, In; X = S, Se, Te) homo- and heterostructures are of interest in electronics and optoelectronics. Structural, electronic and optical properties of bulk and layered MX and GaX/InX heterostructures have been investigated comprehensively using density functional theory (DFT) calculations. Based on the quantum theory of atoms in molecules, topological analyses of bond degree (BD), bond length (BL) and bond angle (BA) have been detailed for interpreting interatomic interactions, hence the structure–property relationship. The X–X BD correlates linearly with the ratio of local potential and kinetic energy, and decreases as X goes from S to Te. For van der Waals (vdW) homo- and heterostructures of GaX and InX, a cubic relationship between microscopic interatomic interaction and macroscopic electromagnetic behavior has been established firstly relating to weighted absolute BD summation and static dielectric constant. A decisive role of vdW interaction in layer-dependent properties has been identified. The GaX/InX heterostructures have bandgaps in the range 0.23–1.49 eV, absorption coefficients over 10−5 cm−1 and maximum conversion efficiency over 27%. Under strain, discordant BD evolutions are responsible for the exclusively distributed electrons and holes in sublayers of GaX/InX. Meanwhile, the interlayer BA adjustment with lattice mismatch explains the constraint-free lattice of the vdW heterostructure.

Exploring the Photovoltaic Properties of Metal Bipyridine Complexes (Metal = Fe, Zn, Cr, and Ru) by Density Functional Theory

2018 ◽  
Vol 73 (4) ◽  
pp. 337-344 ◽  
Author(s):  
Ahmad Irfan ◽  
Ghulam Abbas
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Photovoltaic Performance ◽  
Open Circuit ◽  
Band Alignment ◽  
Structure Property ◽  
Ambient Conditions ◽  
Photovoltaic Properties ◽  
Functional Theory ◽  
Solar Cell Performance

AbstractThe synthesis and characterisation of mononuclear Fe complexes were carried out by using bipyridine (Compound 1) at ambient conditions. Additionally, three more derivatives were designed by substituting the central Fe metal with Zn, Cr, and Ru (Compound 2, Compound 3, and Compound 4), respectively. The ground state geometry calculations were carried out by using density functional theory (DFT) at B3LYP/6-31G** (LANL2DZ) level of theory. We shed light on the frontier molecular orbitals, electronic properties, photovoltaic parameters, and structure–property relationship. The open-circuit voltage is a promising parameter that considerably affects the photovoltaic performance; thus, we have estimated its value by considering the complexes as donors whereas TiO2 and/or Si were used as acceptors. The solar cell performance behaviour was also studied by shedding light on the band alignment and energy level offset.

STABLE STRUCTURES AND CHARACTERISTIC VIBRATIONAL SPECTRA OF TinOm(n = 2–4; m = 1–2n) CLUSTERS

2013 ◽  
Vol 12 (01) ◽  
pp. 1250094 ◽  
Author(s):  
HONGBO DU ◽  
YU JIA ◽  
RUI-QIN ZHANG
Keyword(s):  
Density Functional Theory ◽  
Raman Spectrum ◽  
Density Functional ◽  
Structure Property ◽  
Functional Theory ◽  
Experimental Identification ◽  
Structure Property Relationships ◽  
Method Of Density Functional ◽  
Ir And Raman ◽  
Stable Structures

The energetically favorable structures and characteristic infrared (IR) and Raman peaks of Ti n O m(n = 2–4, m ≤ 2n) clusters are obtained in this work using a B3LYP/6-311G(d) method of density functional theory (DFT). The structures with m < 2n compose of Ti atoms of lower numbers of coordination with O atoms, providing many dangling bonds which considerably enhance the reactivity compared with its bulk counterpart. Two- and three-coordinated O atoms present for m/n ≤ 1.5, whereas two- and also single-coordinated O atoms are found for m/n > 1.5. The Ti n O m(n = 2–4, m < 2n) clusters show strong IR peaks in the range of 600–1100 cm-1 and strong Raman peaks in the region of 300–800 cm-1, whereas both the IR and Raman spectrum peaks of the Ti n O m(n = 2–4, m = 2n) clusters are in the region of 700–1100 cm-1. The main Raman peak of the Ti n O m(m ≠ 2n) clusters is at a frequency considerably lower than that of the IR spectrum. Our results can help understand the structure-property relationships of the Ti n O m clusters and provide their characteristic spectroscope features for further experimental identification.

scholarly journals The phase stability network of all inorganic materials

2020 ◽  
Vol 6 (9) ◽  
pp. eaay5606 ◽  
Author(s):  
Vinay I. Hegde ◽  
Muratahan Aykol ◽  
Scott Kirklin ◽  
Chris Wolverton
Keyword(s):  
Phase Stability ◽  
Density Functional ◽  
Materials Science ◽  
Inorganic Materials ◽  
Structure Property ◽  
Two Phase ◽  
Functional Theory ◽  
Structure Property Relationships ◽  
Complementary Approach ◽  
Tie Line

One of the holy grails of materials science, unlocking structure-property relationships, has largely been pursued via bottom-up investigations of how the arrangement of atoms and interatomic bonding in a material determine its macroscopic behavior. Here, we consider a complementary approach, a top-down study of the organizational structure of networks of materials, based on the interaction between materials themselves. We unravel the complete “phase stability network of all inorganic materials” as a densely connected complex network of 21,000 thermodynamically stable compounds (nodes) interlinked by 41 million tie line (edges) defining their two-phase equilibria, as computed by high-throughput density functional theory. Analyzing the topology of this network of materials has the potential to uncover previously unidentified characteristics inaccessible from traditional atoms-to-materials paradigms. Using the connectivity of nodes in the phase stability network, we derive a rational, data-driven metric for material reactivity, the “nobility index,” and quantitatively identify the noblest materials in nature.

Computational study on thermally activated delayed fluorescence of donor–linker–acceptor network molecules

RSC Advances ◽  
2016 ◽  
Vol 6 (43) ◽  
pp. 37203-37211 ◽  
Author(s):  
Talapunur Vikramaditya ◽  
Mukka Saisudhakar ◽  
Kanakamma Sumithra
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Organic Molecules ◽  
Computational Study ◽  
Delayed Fluorescence ◽  
Structure Property ◽  
Functional Theory ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Structure Property Relationships

Using density functional theory we have investigated the structure–property relationships of organic molecules with a donor–linker–acceptor (DLA) framework, which can be used as precursors of OLED materials.

scholarly journals Mixed-linker UiO-66: structure–property relationships revealed by a combination of high-resolution powder X-ray diffraction and density functional theory calculations

2017 ◽  
Vol 19 (2) ◽  
pp. 1551-1559 ◽  
Author(s):  
Marco Taddei ◽  
Davide Tiana ◽  
Nicola Casati ◽  
Jeroen A. van Bokhoven ◽  
Berend Smit ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
High Resolution ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Structure Property Relationships

Structure–property relationships in mixed-linker UiO-66 were disclosed using high-resolution powder X-ray diffraction and density functional theory calculations.

Contrasting 1D tunnel-structured and 2D layered polymorphs of V2O5: relating crystal structure and bonding to band gaps and electronic structure

2016 ◽  
Vol 18 (23) ◽  
pp. 15798-15806 ◽  
Author(s):  
Thomas M. Tolhurst ◽  
Brett Leedahl ◽  
Justin L. Andrews ◽  
Peter M. Marley ◽  
Sarbajit Banerjee ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Band Gaps ◽  
Structure Property ◽  
Functional Theory ◽  
X Ray ◽  
Structure Property Relationships ◽  
Structure And Bonding

An elucidation of structure–property relationships in V2O5 polymorphs using synchrotron X-ray spectroscopy and density functional theory calculations.

scholarly journals Structure-property relationships in organic battery anode materials: exploring redox reactions in crystalline Na- and Li-benzene diacrylate using combined crystallography and density functional theory calculations

2021 ◽  
Author(s):  
Rodrigo Carvalho ◽  
Cleber Marchiori ◽  
Viorica-Alina Oltean ◽  
Stéven Renault ◽  
Tom Willhammar ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Anode Materials ◽  
Redox Reactions ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Structure Property ◽  
Functional Theory ◽  
Structure Property Relationships ◽  
New Generation ◽  
Battery Anode

Organic-based materials are potential candidates for a new generation of sustainable and environmentally friendly battery technologies, but insights are currently missing into the structural, kinetic and thermodynamic properties of how...

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