Computational Condensed Matter最新文献

{"title":"Electronic and optical properties of few-layer Bi2Te3 via DFT analysis","authors":"R. Flores-Cruz ,&nbsp;M. Arteaga-Varela ,&nbsp;J. de J. Pelayo-Cárdenas ,&nbsp;H. Gómez-Pozos ,&nbsp;V. Rodríguez-Lugo","doi":"10.1016/j.cocom.2026.e01221","DOIUrl":"10.1016/j.cocom.2026.e01221","url":null,"abstract":"<div><div>This study investigates the effect of layer thickness on the electronic and optical properties of the topological insulator Bi₂Te₃. Calculations were performed for a single quintuple layer (1QL) and a two-quintuple-layer (2QL) system. Increasing the number of layers reduces the electronic band gap from 0.24 eV in 1QL to 0.017 eV in 2QL due to weakened surface interactions and reduced quantum confinement. Optical properties, including the dielectric function, refractive index, and reflectivity, are significantly enhanced with additional layers. The refractive index increases from <em>n</em>_<em>x</em> = 3.19 to 4.45 and <em>n</em>_<em>z</em> = 2.60 to 3.87, while reflectivity rises from 0.27 to 0.40 in x and 0.20 to 0.34 in z. These results show that layer thickness is an effective tool to tune electronic and optical properties without doping, highlighting Bi₂Te₃'s potential for photodetectors, infrared sensors, and solar energy applications.</div></div>","PeriodicalId":46322,"journal":{"name":"Computational Condensed Matter","volume":"46 ","pages":"Article e01221"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Piezoelectric response in quasi-2D XMSiN2 (X = S, Se, Te; M = Mo, W) monolayers: Substrate effect","authors":"A.I. Kochaev ,&nbsp;R.T. Sibatov","doi":"10.1016/j.cocom.2026.e01225","DOIUrl":"10.1016/j.cocom.2026.e01225","url":null,"abstract":"<div><div>A computational framework is presented to investigate the vertical interface coupling between quasi-2D asymmetric XMSiN<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> (X = S, Se, Te; M = Mo, W) monolayers and a boron nitride substrate. The excellent lattice match between these materials eliminates the need for large supercells in first-principles calculations, enabling precise characterization of the interface properties. The calculations of the piezoelectric coefficients reveal a significant modulation of the piezoelectric response in <em>h</em>-BN–XMSiN<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> and XMSiN<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>–<em>h</em>-BN heterostructures. This modulation is attributed to the intrinsic piezoelectricity of the boron nitride substrate. This finding emphasizes the critical importance of substrate effects in the design of nano-acoustoelectronic devices. The obtained piezoelectric coefficients suggest that XMSiN<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> monolayers possess performance characteristics comparable to conventional piezoelectrics, making them a promising candidate for high-frequency applications such as surface acoustic wave devices, signal filters, and delay lines in modern acoustoelectronics.</div></div>","PeriodicalId":46322,"journal":{"name":"Computational Condensed Matter","volume":"46 ","pages":"Article e01225"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146037514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Suitability of two-dimensional TaS2 anodes for Li, Na and Mg rechargeable batteries: A first-principles study","authors":"Mohammad Nouman ,&nbsp;Brajesh Kumar ,&nbsp;Sudhir Kumar","doi":"10.1016/j.cocom.2026.e01235","DOIUrl":"10.1016/j.cocom.2026.e01235","url":null,"abstract":"<div><div>A first-principles study of two different two-dimensional (2D) polytypes (1T and 1H) of layered TaS₂ is performed to find their application as anodes in lithium (Li), sodium (Na) and magnesium (Mg) ion batteries. The structural stability of these monolayers is confirmed through <em>Ab-initio</em> Molecular Dynamics (AIMD) simulations at finite temperatures. The lattice constants of the monolayers are <span><math><mo>∼</mo></math></span>1% larger than their respective bulk phases. The calculated charge transfer, low diffusion barrier and low average open-circuit voltage (OCV) makes 1H monolayer a promising candidate among anodes for Li and Na ion batteries, revealing a theoretical storage capacity of 437 mAhg⁻¹. The 1T monolayer reveals a capacity of 219 mAhg⁻¹ for Li while 437 mAhg⁻¹ for Na. Additionally, our calculations predict insignificant lattice strain between 0.3% to 3% during charging and discharging processes, critical for battery life and its performance. However, these monolayers are found to be inadequate for applications as anodes in Mg-ion batteries, we hope that the present results will help experimentalists and engineers to develop next-generation rechargeable batteries.</div></div>","PeriodicalId":46322,"journal":{"name":"Computational Condensed Matter","volume":"46 ","pages":"Article e01235"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146188146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First principles study of pristine and Mn-doped Cs2SnX6 (X = Cl, Br, I): A multifunctional perspective for optoelectronic and thermoelectric applications","authors":"Akshara Bhalani,&nbsp;N.K. Bhatt","doi":"10.1016/j.cocom.2025.e01199","DOIUrl":"10.1016/j.cocom.2025.e01199","url":null,"abstract":"<div><div>Lead-free vacancy-ordered double perovskites offer stable, nontoxic alternatives to Pb-halide semiconductors, yet the impact of transition-metal incorporation remains unexplored. Using first-principles calculations, we unveil how Mn incorporation alters the structural, electronic, optical, and thermoelectric behavior of Cs₂SnX₆ (X = Cl, Br, I). The studied all compositions satisfy mechanical stability criteria, and phonon dispersion confirms the dynamical stability of the pristine structures. Mn incorporation induces a halogen-dependent mechanical response. Electronic structure analyses reveal that Mn introduces highly localized 3<em>d</em>-derived intermediate states that substantially narrow the band gap, which is confirmed through charge-density contours, showing strong, localized Mn-X bonding that exceeds native Sn-X interactions. The absorption coefficients show a pronounced redshift of the absorption edge upon alloying, along with a distinct visible-region peak. This behavior arises from the dopant-induced intermediate states introduced into the band structure, which facilitate additional optical transitions by enabling photoexcited carriers to traverse from the valence band to the conduction band. Mn substitution also promotes increased phonon scattering and reduced lattice thermal conductivity, which in turn improves the low-temperature thermoelectric performance of Cs₂SnI₆:Mn, while pristine Cs₂SnI₆ retains the most favorable high-temperature ZT. Together, computed results elucidate how Mn substitution simultaneously reshapes the electronic and phononic properties of Cs₂SnX₆, offering fundamental guidance for designing lead-free perovskites with tunable OE and TE functionalities.</div></div>","PeriodicalId":46322,"journal":{"name":"Computational Condensed Matter","volume":"46 ","pages":"Article e01199"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First-principles DFT study of the structural, elastic, optoelectronic, and thermoelectric properties of GaSnX3 (X = Br, I) perovskites","authors":"Ali Aissani ,&nbsp;Anissa Besbes ,&nbsp;Radouan Djelti ,&nbsp;Ouendadji Salima ,&nbsp;Lakhdar Benahmedi ,&nbsp;Sid Ahmed Bendehiba","doi":"10.1016/j.cocom.2026.e01227","DOIUrl":"10.1016/j.cocom.2026.e01227","url":null,"abstract":"<div><div>This study presents a detailed first-principles investigation of the structural, electronic, optical, mechanical, and thermoelectric properties of GaSnX₃ (X = Br, I) perovskite-like compounds using density functional theory (DFT). Structural optimization indicates that both GaSnX₃ and GaSnI₃ adopt a cubic perovskite-like framework at the ground state, with lattice constants of 5.81 Å and 6.18 Å, respectively. Electronic structure calculations using the Generalized Gradient Approximation (GGA-PBE) and Tight-Binding Modified Becke-Johnson (TB-mBJ) potentials reveal semiconducting behavior, with direct band gaps of 0.20 eV and 0.26 eV (GGA-PBE) and corrected values of 0.79 eV and 0.40 eV (TB-mBJ). Optical absorption calculations show onsets extending into the visible range for the iodide compound, suggesting potential relevance for optoelectronic applications where band-gap tunability is important. The calculated elastic constants satisfy the Born criteria and reflect the intrinsically soft nature of halide perovskite-like materials, which may be advantageous in thin-film and flexible configurations rather than indicating conventional mechanical robustness. Thermoelectric properties were analyzed within the constant relaxation time approximation, focusing on the electronic contribution; the obtained electronic figure of merit (ZT_e) represents an upper theoretical limit, as lattice thermal conductivity was not included. Overall, this study provides a coherent theoretical description of GaSnX₃ compounds, highlighting structure–property relationships and emphasizing the need for further investigations incorporating phonon transport, finite-temperature effects, and experimental validation.</div></div>","PeriodicalId":46322,"journal":{"name":"Computational Condensed Matter","volume":"46 ","pages":"Article e01227"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146077581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Next-Generation lead-free halide perovskites: CsInX3 (X = Br, Cl) for high-efficiency solar cells","authors":"Safae Tourougui,&nbsp;Mohamed Alla,&nbsp;Hicham El-assib,&nbsp;Mustapha Rouchdi,&nbsp;Boubker Fares","doi":"10.1016/j.cocom.2025.e01193","DOIUrl":"10.1016/j.cocom.2025.e01193","url":null,"abstract":"<div><div>Halide perovskite materials have emerged as highly promising candidates for next-generation photovoltaic technology due to their tunable chemistry and remarkable optoelectronic properties. In this study, we investigated the structural, phonon, electronic, and optical properties of cubic inorganic halide perovskites CsInX₃ (X = Br, Cl) using density functional theory (DFT) with PBE-GGA and mBJ-GGA exchange correlation potentials. The results reveal indirect bandgaps of 0.94 (1.19) eV for CsInBr₃ and 1.07 (2.11) eV for CsInCl₃, along with strong optical absorption in the visible and near-infrared regions, high conductivity, and low reflectivity features desirable for solar energy conversion. To further assess their device potential, these materials were implemented in a solar cell model (ITO/SnS₂/CsInX₃/CBTS/Au) using SCAPS-1D simulations. Optimization of device parameters yielded promising power conversion efficiencies of up to 24.52 % for CsInBr₃ and 17.39 % for CsInCl₃. These findings highlight the potential of CsInX₃ perovskites as lead-free absorbers for high-performance photovoltaic applications.</div></div>","PeriodicalId":46322,"journal":{"name":"Computational Condensed Matter","volume":"46 ","pages":"Article e01193"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Resonant tunnelling and conductance evolution in PHOTH-G nanoribbons: From sharp resonances to broad bands","authors":"Francenildo Baia Reis ,&nbsp;Jordan Del Nero","doi":"10.1016/j.cocom.2026.e01223","DOIUrl":"10.1016/j.cocom.2026.e01223","url":null,"abstract":"<div><div>We report quantum-transport simulations of two-terminal PHOTH-graphene nanoribbon (PHOTH-GNR) devices that display a width-driven crossover from resonant tunneling to multichannel conduction. PHOTH-graphene is a two-dimensional allotrope of metallic carbon composed of mixed rings of four to eight members. We model symmetric PHOTH-GNRs with width W = 1–4 (3.98 Å unit cell) and compute band structures, transmission spectra, I–V curves and Fowler–Nordheim plots. Although all ribbons are nominally metallic, transport varies strongly with W: W = 1 shows low zero-bias conductance with discrete transmission resonances, sharp dI/dV peaks and an apparent FN threshold near 0.5–0.6 V (G_max ≈ 79.7 μS; I_max ≈ 24.85 μA). Increasing W broadens transmission features, raises the DOS at E_F and lowers effective barriers: W = 2 exhibits broader resonances; W = 3 develops overlapping plateaus and finite zero-bias current; W = 4 is nearly Ohmic (G_max ≈ 232.2 μS; I_max ≈ 117.24 μA). The principal transmission peak FWHM increases from ≈0.04 to ≈0.24 eV while cohesive energy deepens from −7.76 to −8.40 eV/atom. FN analysis classifies W = 1–2 as tunneling-dominated and W = 3–4 as field-emission. Ribbon width therefore tunes PHOTH-GNRs between sharp resonant switches and smooth multi-channel interconnects.</div></div>","PeriodicalId":46322,"journal":{"name":"Computational Condensed Matter","volume":"46 ","pages":"Article e01223"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146037513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural, electronic, and magnetic properties of N, P, As, Sb, and Bi dopants in 2D monolayer SiC for high-power electronic application","authors":"E. Igumbor ,&nbsp;E. Mapasha ,&nbsp;A.T. Raji","doi":"10.1016/j.cocom.2026.e01219","DOIUrl":"10.1016/j.cocom.2026.e01219","url":null,"abstract":"<div><div>Point defects play a crucial role in semiconductors, as they can be used to modify and enhance device performance. Two-dimensional (2D) SiC is a newly synthesized layered material, and unlike bulk SiC, limited information is available regarding the impact of point defects in 2D monolayer SiC. In this study, hybrid density functional theory was employed to investigate the formation, structural, electronic, and magnetic properties of N, P, As, Sb, and Bi dopants in 2D monolayer SiC. While the N, P, As, and Bi are more energetically favorable when substituted at the C site under the C-rich conditions, the Sb is more energetically stable when substituted at the Si site on the C-rich growth conditions. The N, As, Sb, and Bi induce stronger total magnetic moments when substituted at C sites than at Si sites. While N acts as an electron acceptor regardless of the lattice site it occupies, Bi behaves as an electron donor when substituted at either the C or Si lattice site. P, As, and Sb act as electron donors or acceptors when substituted at the C or Si lattice sites, respectively. The N<span><math><msub><mrow></mrow><mrow><mi>C</mi></mrow></msub></math></span> defect concentration remains extremely low at all temperatures, whereas the P<span><math><msub><mrow></mrow><mrow><mi>C</mi></mrow></msub></math></span> defect exhibits behavior characteristic of thermally activated processes. The P<span><math><msub><mrow></mrow><mrow><mi>Si</mi></mrow></msub></math></span> defect shows a relatively high concentration even at low temperatures (300 K), while the As<span><math><msub><mrow></mrow><mrow><mi>C</mi></mrow></msub></math></span> defect displays limited thermal activation but remains thermodynamically favorable at elevated temperatures. The density of states plots show that when N, As, and Sb are substituted at the C lattice sites, the 2D monolayer SiC exhibits n-type semiconducting behavior. In contrast, when Bi is substituted at the C site, the 2D monolayer SiC behaves as a p-type semiconductor. The Sb, As, N, and P dopants introduce sharp mid-gap states within the band gap of 2D monolayer SiC. In addition, N, P, As, Sb, and Bi induce strong spin polarization in the material. Overall, this study provides theoretical insights into defect engineering in 2D monolayer SiC, highlighting its potential for future optoelectronic and electronic applications.</div></div>","PeriodicalId":46322,"journal":{"name":"Computational Condensed Matter","volume":"46 ","pages":"Article e01219"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of physical properties of the double perovskite Cs2RbBiCl6","authors":"A. Jabar ,&nbsp;S. Idrissi ,&nbsp;L. Bahmad","doi":"10.1016/j.cocom.2026.e01217","DOIUrl":"10.1016/j.cocom.2026.e01217","url":null,"abstract":"<div><div>This study presents a first-principles investigation of the structural, mechanical, electronic, optical, and thermoelectric properties of the double perovskite Cs₂RbBiCl₆ material using density functional theory with the GGA-PBE approximation. Structural analysis determined the equilibrium lattice constant (11.996 Å) and bulk modulus (18.975 GPa), confirming moderate compressibility and structural stability. Mechanical properties, including elastic constants and moduli, demonstrated anisotropic behavior and mechanical stability, satisfying Born's criteria. The electronic structure calculations revealed an indirect wide band gap of 3.998 eV, confirming the semiconducting nature of Cs₂RbBiCl₆, with Bi p-states dominating the conduction band and Cl p-states defining the valence band. Furthermore, the optical properties, including the dielectric function, optical conductivity, refractive index, reflectivity, and absorption coefficient, indicated strong absorption and reflection in the 5–6 eV range. The electron energy loss spectrum exhibited plasmon resonances and electronic excitations, correlating with high absorption in the optical range. Thermoelectric calculations, performed using the BoltzTraP code, revealed a high Seebeck coefficient at low temperatures and optimal thermoelectric performance around 400 K. Both electrical and thermal conductivities increased with temperature up to 600 K, followed by a decline due to carrier scattering effects. The figure of merit (ZT) peaked at approximately 400 K, indicating potential applications in thermoelectric devices.</div></div>","PeriodicalId":46322,"journal":{"name":"Computational Condensed Matter","volume":"46 ","pages":"Article e01217"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantum transport simulation of Sub-5nm monolayer SiC MOSFET: The underlap-structure impact","authors":"Wen-Bo Yuan ,&nbsp;Qin Xiang ,&nbsp;Hong-Lin Ma ,&nbsp;Hui Xie ,&nbsp;Lei Hu ,&nbsp;Zhi-Qiang Fan","doi":"10.1016/j.cocom.2026.e01236","DOIUrl":"10.1016/j.cocom.2026.e01236","url":null,"abstract":"<div><div>As Moore's Law approaches the physical limit, searching for stable and excellent channel materials at sub-5nm becomes a significant challenge. Due to the high stability and high carrier mobility, monolayer SiC (ML-SiC) is a hopeful candidate for next-generation electronics. Nevertheless, sub-5nm ML-SiC metal-oxide semiconductor field-effect transistors (MOSFETs) have received limited investigation. Herein, the ballistic transport properties of sub-5nm ML-SiC MOSFETs are explored using first-principles quantum transport theory, focusing on the underlap structure (<em>UL</em>-structure) role. Theoretical results find that, with the <em>UL</em>-structure introduction, the electrical performance of ML-SiC MOSFETs has been continuously optimized, and its driving current remains at a high level and the gate control capability is enhanced. The <em>UL</em>-structure effectively reduces the channel capacitance and suppresses the source-drain tunneling current, which synergistically enhances the gate control over the channel. More precisely, 3 nm is identified as the best <em>UL</em>-structure scale to optimize ML-SiC MOSFETs.</div></div>","PeriodicalId":46322,"journal":{"name":"Computational Condensed Matter","volume":"46 ","pages":"Article e01236"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}