2D Materials最新文献

{"title":"Dipolar interactions enhanced by two-dimensional dielectric screening in few-layer van der Waals structures","authors":"Yuhang Hou, Hongyi Yu","doi":"10.1088/2053-1583/ad2525","DOIUrl":"https://doi.org/10.1088/2053-1583/ad2525","url":null,"abstract":"We theoretically examined how the dielectric screening of two-dimensional (2D) layered materials affects the dipolar interaction between interlayer excitons (IXs) in few-layer van der Waals structures. Our analysis indicates that the dipolar interaction is largely enhanced by 2D dielectric screening at an inter-exciton separation of several nanometers or larger. The underlying mechanism can be attributed to the induced-charge densities in layered materials, which give rise to induced-dipole densities at large distances with directions parallel to that of the IX. The interaction between quadrupolar excitons in trilayer structures are found to be enhanced even larger, with a magnitude one to two orders stronger than that without 2D dielectric screening. The strengths of these dipolar and quadrupolar interactions can be further tuned by engineering the dielectric environment.","PeriodicalId":6812,"journal":{"name":"2D Materials","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140010447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New twisted van der Waals fabrication method based on strongly adhesive polymer","authors":"Giung Park, Suhan Son, Jongchan Kim, Yunyeong Chang, Kaixuan Zhang, Miyoung Kim, Jieun Lee, Je-Geun Park","doi":"10.1088/2053-1583/ad2524","DOIUrl":"https://doi.org/10.1088/2053-1583/ad2524","url":null,"abstract":"Observations of emergent quantum phases in twisted bilayer graphene prompted a flurry of activities in van der Waals (vdW) materials beyond graphene. Most current twisted experiments use a so-called tear-and-stack method using a polymer called polypropylene carbonate (PPC). However, despite the clear advantage of the current PPC tear-and-stack method, there are also technical limitations, mainly a limited number of vdW materials that can be studied using this PPC-based method. This technical bottleneck has been preventing further development of the exciting field beyond a few available vdW samples. To overcome this challenge and facilitate future expansion, we developed a new tear-and-stack method using a strongly adhesive polycaprolactone. With similar angular accuracy, our technology allows fabrication without a capping layer, facilitating surface analysis and ensuring inherently clean interfaces and low operating temperatures. More importantly, it can be applied to many other vdW materials that have remained inaccessible with the PPC-based method. We present our results on twist homostructures made with a wide choice of vdW materials—from two well-studied vdW materials (graphene and MoS₂) to the first-ever demonstrations of other vdW materials (NbSe₂, NiPS₃, and Fe₃GeTe₂). Therefore, our new technique will help expand moiré physics beyond few selected vdW materials and open up more exciting developments.","PeriodicalId":6812,"journal":{"name":"2D Materials","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140010445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"When 2D Materials meet metals","authors":"L. Pirker, Jan Honolka, Matěj Velický, Otakar Frank","doi":"10.1088/2053-1583/ad286b","DOIUrl":"https://doi.org/10.1088/2053-1583/ad286b","url":null,"abstract":"\u0000 This review delves into the intricacies of the interfaces formed between two-dimensional (2D) materials and metals, exploring a realm rich with fundamental insights and promising applications. Historically, our understanding of 2D materials emanated from studies employing dielectric substrates or suspended samples. However, integrating metals in the exfoliation and growth processes of 2D materials has opened up new avenues, unveiling various shades of interactions ranging from dispersive forces to covalent bonding. The resulting modifications in 2D materials, particularly transition metal dichalcogenides (TMDCs), offer more than a theoretical intrigue. They bear substantial implications for (opto)electronics, altering Schottky barrier heights and contact resistances in devices. We explore metal-mediated methods for TMDC exfoliation, elucidating the mechanisms and their impact on TMDC-metal interactions. Delving deeper, we scrutinize the fundamentals of these interactions, focusing primarily on MoS2 and Au. Despite the recent surge of interest and extensive studies, critical gaps remain in our understanding of these intricate interfaces. We discuss controversies, such as the changes in Raman or photoemission signatures of MoS2 on Au, and propose potential explanations. The interplay between charge redistribution, substrate-induced bond length variations, and interface charge transfer processes are examined. Finally, we address the intriguing prospect of TMDC phase transitions induced by strongly interacting substrates and their implications for contact design.","PeriodicalId":6812,"journal":{"name":"2D Materials","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139844242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"When 2D Materials meet metals","authors":"L. Pirker, Jan Honolka, Matěj Velický, Otakar Frank","doi":"10.1088/2053-1583/ad286b","DOIUrl":"https://doi.org/10.1088/2053-1583/ad286b","url":null,"abstract":"\u0000 This review delves into the intricacies of the interfaces formed between two-dimensional (2D) materials and metals, exploring a realm rich with fundamental insights and promising applications. Historically, our understanding of 2D materials emanated from studies employing dielectric substrates or suspended samples. However, integrating metals in the exfoliation and growth processes of 2D materials has opened up new avenues, unveiling various shades of interactions ranging from dispersive forces to covalent bonding. The resulting modifications in 2D materials, particularly transition metal dichalcogenides (TMDCs), offer more than a theoretical intrigue. They bear substantial implications for (opto)electronics, altering Schottky barrier heights and contact resistances in devices. We explore metal-mediated methods for TMDC exfoliation, elucidating the mechanisms and their impact on TMDC-metal interactions. Delving deeper, we scrutinize the fundamentals of these interactions, focusing primarily on MoS2 and Au. Despite the recent surge of interest and extensive studies, critical gaps remain in our understanding of these intricate interfaces. We discuss controversies, such as the changes in Raman or photoemission signatures of MoS2 on Au, and propose potential explanations. The interplay between charge redistribution, substrate-induced bond length variations, and interface charge transfer processes are examined. Finally, we address the intriguing prospect of TMDC phase transitions induced by strongly interacting substrates and their implications for contact design.","PeriodicalId":6812,"journal":{"name":"2D Materials","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139784554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"X-ray photoelectron diffraction as a modern tool for determining surface stacking sequence in layered materials","authors":"L H de Lima, A de Siervo","doi":"10.1088/2053-1583/ad2526","DOIUrl":"https://doi.org/10.1088/2053-1583/ad2526","url":null,"abstract":"We investigated the surface structure of a NbSe₂ single crystal at room temperature, using angle-scanned x-ray photoelectron diffraction (XPD) combined with multiple scattering calculations. Different stacking sequences were tested (1T, 2H_{\u0000<italic toggle=\"yes\">a</italic>\u0000}, 2H_{\u0000<italic toggle=\"yes\">c</italic>\u0000}, and 3R), including possible stacking faults and a mixed 2H–3R stacking proposed earlier in the literature. We confirm the capability of XPD to distinguish different proposed structural models and, unambiguously, determine the true surface structure. Also, our findings provide reliable in-plane and interlayer distances. We observed expansions of the perpendicular distances between atomic planes within the monolayer and between monolayers of 3%–5%. These results are important as accurate experimental input for the development of theoretical methods that involve a quantitative description of van der Waals systems.","PeriodicalId":6812,"journal":{"name":"2D Materials","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139757274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Search on stable binary and ternary compounds of two-dimensional transition metal halides","authors":"D. Hvazdouski, Мaryia Baranava, Elena A. Korznikova, A. Kistanov, Viktor R. Stempitsky","doi":"10.1088/2053-1583/ad2692","DOIUrl":"https://doi.org/10.1088/2053-1583/ad2692","url":null,"abstract":"\u0000 Ab initio driven density functional theory (DFT)-based high throughput simulations have been conducted to search for stable two-dimensional (2D) structures based on transition metal halides. Binary MeX2 and MeXY (Me – transition element, X and Y – Cr, Br, I, where X ≠ Y) 2D structures in two structural polymorphic modifications, which are 1T- phase and 1H-phase, have been studied. The main structural stability criteria, such as heat formation energy, elasticity constants, and phonon spectra and the following ab initio molecular dynamics (AIMD) simulations have been used to determine the stability of studied compounds. It has been shown that 35 MeX2 and 32 MeXY 2D structures comply with given stability criteria. Photocatalytic properties of these stable 2D MeX2 and 2D MeXY have been investigated. Based on the calculated band gap size Eg, work function Ф and electron affinity χ, it has been found that among all stable compounds 13 MeX2 and 16 MeXY 2D structures are promising photocatalysts for water splitting. However, only 7 compounds have solar-to-hydrogen (STH) efficiency overcome the 10% threshold, which is a critical parameter for solar hydrogen generation to be an economically viable resource. Among MeX2 2D structures 1T-CdI2 and 1H-VBr2 possess a STH efficiency of 11.58% and 17.23%. In the case of 2D MeXY, STH efficiencies are 22.79% (1T-ZnClI), 15.20% (1T-CdClI), 22.13% (1T-ZnBrI), 12.11% (1T-CdBrI) and 19.76% (1H-VClBr). Moreover, as a result of this work, a comprehensive publicly available database, containing detailed calculation parameters and fundamental properties of the discovered 2D transition metal halides, has been created.","PeriodicalId":6812,"journal":{"name":"2D Materials","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139859872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Search on stable binary and ternary compounds of two-dimensional transition metal halides","authors":"D. Hvazdouski, Мaryia Baranava, Elena A. Korznikova, A. Kistanov, Viktor R. Stempitsky","doi":"10.1088/2053-1583/ad2692","DOIUrl":"https://doi.org/10.1088/2053-1583/ad2692","url":null,"abstract":"\u0000 Ab initio driven density functional theory (DFT)-based high throughput simulations have been conducted to search for stable two-dimensional (2D) structures based on transition metal halides. Binary MeX2 and MeXY (Me – transition element, X and Y – Cr, Br, I, where X ≠ Y) 2D structures in two structural polymorphic modifications, which are 1T- phase and 1H-phase, have been studied. The main structural stability criteria, such as heat formation energy, elasticity constants, and phonon spectra and the following ab initio molecular dynamics (AIMD) simulations have been used to determine the stability of studied compounds. It has been shown that 35 MeX2 and 32 MeXY 2D structures comply with given stability criteria. Photocatalytic properties of these stable 2D MeX2 and 2D MeXY have been investigated. Based on the calculated band gap size Eg, work function Ф and electron affinity χ, it has been found that among all stable compounds 13 MeX2 and 16 MeXY 2D structures are promising photocatalysts for water splitting. However, only 7 compounds have solar-to-hydrogen (STH) efficiency overcome the 10% threshold, which is a critical parameter for solar hydrogen generation to be an economically viable resource. Among MeX2 2D structures 1T-CdI2 and 1H-VBr2 possess a STH efficiency of 11.58% and 17.23%. In the case of 2D MeXY, STH efficiencies are 22.79% (1T-ZnClI), 15.20% (1T-CdClI), 22.13% (1T-ZnBrI), 12.11% (1T-CdBrI) and 19.76% (1H-VClBr). Moreover, as a result of this work, a comprehensive publicly available database, containing detailed calculation parameters and fundamental properties of the discovered 2D transition metal halides, has been created.","PeriodicalId":6812,"journal":{"name":"2D Materials","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139800193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Superconductivity and electron self-energy in tungsten-sulfur-hydride monolayer","authors":"Jakkapat Seeyangnok, M. M. Ul Hassan, U. Pinsook, Graeme Ackland","doi":"10.1088/2053-1583/ad2523","DOIUrl":"https://doi.org/10.1088/2053-1583/ad2523","url":null,"abstract":"\u0000 Hydrogen-rich structures have recently gained attention as a candidate for room-temperature superconductors. Hydrogen has high phonon frequencies and can be an ideal component for superconductors if it also exhibits strong electronphonon coupling. In bulk materials, this has been achieved only under very high pressure. Two-dimensional (2D) hydrogen-decorated materials can also be expected to become superconductors. Recently, it was shown that a Janus MoSH monolayer can be synthesized [1], and a theoretical investigation of this MoSH monolayer claimed that Tc = 28.58K at atmospheric pressure [2]. In this work, we propose that tungsten sulfur hydride (WSH) is also a superconducting Janus monolayer. The Tc is carefully calculated with very high resolution via the Eliashberg spectral function and the electron self-energy. We find that WSH is a conventional BCS superconductor with Tc = 12.2K at ambient pressure. For practical applications, sensitive dependence on substrate is inferred. We also reported the electron self-energy of WSH, which can be compared directly with future measurements from angle-resolved photoelectron spectroscopy (ARPES).","PeriodicalId":6812,"journal":{"name":"2D Materials","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139683672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unraveling the mechanism of vanadium self-intercalation in 1T-VSe2: atomic-scale evidence for phase transition and superstructure model for intercalation compound","authors":"Daliang He, Bo Wang, Wang Cao, Yongjun Jiang, Sheng Dai, Wei Zhao, Xiaodong Cui, Chuanhong Jin","doi":"10.1088/2053-1583/ad2193","DOIUrl":"https://doi.org/10.1088/2053-1583/ad2193","url":null,"abstract":"Self-intercalation is an efficient strategy for tailoring the property of layer structured materials like transition metal dichalcogenides (TMDCs), while the associated kinetics and mechanism remain scarcely explored. In this study, we investigate the atomic-scale dynamics and mechanism of vanadium (V) self-intercalation in multi-layer 1T-VSe₂ using <italic toggle=\"yes\">in situ</italic> high resolution scanning transmission electron microscopy. The results reveal that the self-intercalation of V induces structural transformation of pristine VSe₂ into three V-enrich intercalated compounds, i.e. V₅Se₈, V₃Se₄ and VSe. The self-intercalated V follows an ordered arrangement of <inline-formula>\u0000<tex-math><?CDATA $2 times 2$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mn>2</mml:mn><mml:mo>×</mml:mo><mml:mn>2</mml:mn></mml:math>\u0000<inline-graphic xlink:href=\"tdmad2193ieqn1.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>, <inline-formula>\u0000<tex-math><?CDATA $2 times 1$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mn>2</mml:mn><mml:mo>×</mml:mo><mml:mn>1</mml:mn></mml:math>\u0000<inline-graphic xlink:href=\"tdmad2193ieqn2.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>, and <inline-formula>\u0000<tex-math><?CDATA $1 times 1$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mn>1</mml:mn><mml:mo>×</mml:mo><mml:mn>1</mml:mn></mml:math>\u0000<inline-graphic xlink:href=\"tdmad2193ieqn3.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> within the interlayer octahedral sites, corresponding to an intercalation concentration of 25%, 50% and 100% in V₅Se₈, V₃Se₄ and VSe, respectively. The V intercalants induced lattice distortions to the host 1T-VSe₂ such as the dimerization of neighboring lattice V is observed experimentally, which are further supported by density functional theory (DFT) calculations. Finally, a superstructure model generalizing the possible structures of self-intercalated compounds in layered TMDCs is proposed and then validated by the DFT determined formation energy landscape. This study provides comprehensive insights on the kinetics and mechanism of the self-intercalation in layered TMDC materials, contributing to the precise control for the structure and stoichiometry of self-intercalated TMDC compounds.","PeriodicalId":6812,"journal":{"name":"2D Materials","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139757437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Graphene Roadmap Briefs (No. 3): meta-market analysis 2023","authors":"Thomas Schmaltz, Lorenzo Wormer, Ulrich Schmoch, Henning Döscher","doi":"10.1088/2053-1583/ad1e78","DOIUrl":"https://doi.org/10.1088/2053-1583/ad1e78","url":null,"abstract":"Graphene and related materials (GRMs) promise ample application potential throughout numerous industries. A dedicated graphene market gradually forms around emerging suppliers aspiring to satisfy future demands. Its growth critically depends on the interplay of supply stream maturation and initial utilizations to drive the demand. The present issue of Graphene Roadmap Briefs provides quantitative insights into the current state and future development of the emerging graphene market. We aggregate the underlying expectations and projections from commercial market reports and critically discuss the results. Established science and technology metrics complement our analyses and provide deeper insights into the global market landscape and key actors. In particular, we resolve composites, batteries, and electronics as major application areas likely to drive the overall development of the graphene market towards mass production.<bold>About: Graphene Roadmap Briefs</bold>Graphene Roadmap Briefs highlight key innovation areas impacted by graphene and related materials (GRMs) as well as overarching aspects of GRM innovation status and prospects. The series bases on the evolving technology and innovation roadmap process initiated by the European Graphene Flagship. It covers crucial innovation trends beyond fundamental scientific discovery and applied research on GRM utilization opportunities.","PeriodicalId":6812,"journal":{"name":"2D Materials","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139757180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}