Strain engineering is one of the most promising and effective routes toward continuously tuning electronic optic properties materials, while thermal are generally believed to be insensitive mechanical strain. In this paper, strain-dependent conductivity monolayer silicene under uniform biaxial tension computed by solving phonon Boltzmann transport equation with interatomic force constants extracted from first-principles calculations. Unlike commonly understanding that only slightly decreases...

The thermal transport properties of hexagonal boron nitride nanoribbons (BNNRs) are investigated. By calculating the phonon spectrum and conductance, it is found that BNNRs possess excellent properties. conductance can be comparable to graphene (GNRs) even exceed latter below room temperature. A fitting formula obtained describe features in BNNRs, which reveals a critical role T1.5 dependence determining transport. In addition, an obviously anisotropic phenomenon observed nanoribbons....

A two-dimensional carbon allotrope, Stone-Wales graphene, is identified in stochastic group and graph constrained searches systematically investigated by first-principles calculations. graphene consists of well-arranged defects, it can be constructed through a ${90}^{\ensuremath{\circ}}$ bond rotation $\sqrt{8}\ifmmode\times\else\texttimes\fi{}\sqrt{8}$ supercell graphene. Its calculated energy relative to +149 meV/atom, makes more stable than the most competitive previously suggested...

The energy landscape of carbon is exceedingly complex, hosting diverse and important metastable phases, including diamond, fullerenes, nanotubes graphene. Searching for structures, especially those with large unit cells, in this challenging. Here we use a combined stochastic search strategy employing two algorithms (AIRSS RG2) to apply connectivity constraints cells containing up 100 atoms. We uncover three low polymorphs (Pbam-32, P6/mmm I-43d) new topologies, 32, 36 94 atoms their...

Graphyne, a new allotrope of carbon, is current topic focus in the nanomaterial research community. We investigate thermal transport property graphyne nanoribbons (GYNRs) by using nonequilibrium Green's-function method. The conductance GYNRs only approximately 40$%$ that graphene nanoribbons. A distinct width dependence observed as well. armchair-edged (A-GYNRs) shows linear dependence, while steplike displayed zigzag-edged (Z-GYNRs). Moreover, an A-GYNR larger than Z-GYNR same width,...

Monolayer InP₃ is a promising candidate for realizing multifunctional device that contains both photovoltaic and thermoelectric technologies.

The phonon transport property is a foundation of understanding material and predicting the potential application in mirco/nano devices. In this paper, thermal borophene investigated by combining first-principle calculations Boltzmann equation. At room temperature, lattice conductivity found to be about 14.34 W/mK (error 3%), which much smaller than that graphene (about 3500 W/mK). contributions from different modes are qualified, some with high frequency abnormally play critical role on...

Based on first principles, we predict a new low-energy Stone-Wales graphene SW40, which has an orthorhombic lattice with $Pbam$ symmetry and 40 carbon atoms in its crystalline cell forming well-arranged patterns. The calculated total energy of SW40 is just about 133 meV higher than that graphene, indicating excellent stability exceeds all the previously proposed allotropes. We find exhibits intrinsic type-III Dirac cone [Phys. Rev. Lett. 120, 237403 (2018)] formed by band crossing local...

The discovery of new carbon allotropes with different building blocks and crystal symmetries has long been great interest to broad materials science fields. Herein, we report several hundred predicted by the state-of-the-art RG2 code first-principles calculations. types that were identified in this work span pure sp2, hybrid sp2/sp3, sp3 C–C bonding. All structures globally optimized at level. thermodynamic stability some selected was further validated computing their phonon dispersions....

The previously predicted phagraphene [Wang et al., Nano Lett. 15, 6182 (2015)] and a recently proposed TPH-graphene have been synthesized from fusion of 2,6-polyazulene chain (5–7 chain) in recent experiment [Fan J. Am. Chem. Soc., 141, 17713 (2019)]. Theoretically, can be considered as the combinations 5–7 chains with distinct 6–6–6 4–7–7 interfacial stacking manners, respectively. In this work, we propose another new graphene allotrope, named penta-hex-hepta-graphene (PHH-graphene), which...

The Proton Exchange Membrane (PEM) water electrolyzer is considered promising energy storing means for harnessing variable renewable sources to produce hydrogen. Understanding the internal fluid dynamics, which are often challenging directly observe experimentally, has prompted use of numerical models investigate two-phase flow within PEM electrolyzers. In this study, we provide a comprehensive review prior research focusing on modeling electrolyzers, encompassing both components at...

Effectively engineering the lattice thermal conductivity of materials is a key interest current science community. Pressure or compressive strain one most worthwhile processes to modify transport property materials, due its robust tunability and flexibility realization. While it well documented in literature that application hydrostatic pressure normally increases bulk little work has been performed on abnormal pressure-dependent governing mechanism not fully understood yet. In this paper,...

The configurational space of two-dimensional planar sp2 carbon has been systematically scanned by a random strategy combined with group and graph theory, 1114 new allotropes have identified. These are energetically more favorable than most the previously predicted 120 allotropes. By fitting HSE06 band structures six old structures, we optimize parameters for general transferable tight-binding model high-throughput structure calculations. We identified that there 190 Dirac semimetals, 241...

In this paper, we propose a convenient strategy to accelerate the evaluation of lattice thermal conductivity through combining phonon Boltzmann transport equation (PBTE) and on-the-fly machine learning potential (FMLP). The diamond silicon ($d\text{\ensuremath{-}}\mathrm{Si}$) is evaluated firstly by density functional theory (DFT), FMLP, empirical with PBTE, respectively. results demonstrate proposed integrates prediction accuracy DFT computational speed potential, breaking dilemma...

The discovery of strong four-phonon (4ph) interactions in boron arsenide has spurred significant investigations into the influence higher-order phonon anharmonic scattering on thermal transport materials. Considering special relative regular residual feature and great potential applications thermoelectrics, this study systematically investigates lattice dynamics behavior monolayer group-IVB transition metal dichalcogenides $1T\ensuremath{-}M{X}_{2}...

Thermal transport properties of isotopic-superlattice graphene nanoribbons with zigzag edge (IS-ZGNRs) are investigated. We find that by isotopic superlattice modulation the thermal conductivity a nanoribbon can be reduced significantly. The property IS-ZGNRs strongly depends on period length and mass. As decreases, undergoes transition from decreasing to increasing. This unique phenomenon is explained analyzing phonon transmission coefficient. While effect mass monotone. Larger difference...

Graphyne, an allotrope of graphene, is currently a hot topic in the carbon-based nanomaterials research community. Taking beta-graphyne as example, we performed comprehensive study thermal transport and related thermoelectric properties by means nonequilibrium Green's function (NEGF). Our simulation demonstrated that conductance only approximately 26% graphene counterpart also shows evident anisotropy. Meanwhile, armchair nanoribbons (A-BGYNRs) presents abnormal stepwise width dependence. As...

Using the Nonequilibrium Green's function approach, we investigate thermoelectric properties of gamma-graphyne nanostructures. Compared with graphene nanoribbons (GNRs), (GYNRs) are found to possess superior performance. Its figure merit ZT is about 3∼13 times larger than that in GNRs. Meanwhile, results show efficiency GYNRs decreases as ribbon width increases, while it increases monotonically temperature. For nanojunctions (GYNJs), value dramatically discrepancy between left and right...

Based on first-principles calculations, the ground state configuration (Cmma-CH) of a hydrogenated biphenylene sheet ( Science 2021, 372, 852) is carefully identified from hundreds possible candidates generated by RG2 code Phys. Rev. B. 2018, 97, 014104). Cmma-CH contains four inequivalent benzene molecules in its crystalline cell due to Cmma symmetry. Hydrogen atoms bond carbon each with boat-like (DDUDDU) up/down sequence and reversed boat-1 (UUDUUD) adjacent rings. energetically less...

Newly discovered carbon monolayer 123-E8Y24-1 presents a semimetal nature and possesses robust Dirac nodal line states.

We report and shed light on the intrinsic thermal transport features of biphenylene network (BPN) hydrogenated BPN (HBPN). Both four-phonon scattering hydrogenation can significantly affect lattice conductivity ( κ ) BPN.

Novel carbon allotropes and ternary B–C–N structures with ultrahigh hardness were screened proposed by high-throughput computation. Electronic-level insights into superhard materials provided from machine learning.

It is well known that different bonding networks could bring a wide variety of physical properties to the materials although they hold analogous element and structure features. In this paper, we present first-principles calculation about lattice dynamics phonon transport two-dimensional (2D) boron-rich material BxN (x = 2, 3, 5). The calculations show besides obvious differences in electrical compared h-BN, special environment these also results quite behaviors, where their thermal...

The accurate description of phonon dispersion two-dimensional (2D) materials demonstrates significance in many research fields condensed matter physics. In this paper, we systematically calculate the spectra and transport properties six representative 2D (encompassing single-element binary compounds with flat, buckled, puckered backbone geometries) by means density functional theory (DFT) two machine learning interatomic potentials [MLIPs, on-the-fly potential (FMLP), moment tensor (MTP)]....