Purevlkham Myagmarsereejid, Selengesuren Suragtkhuu, Quang Thang Trinh, Tim Gould, Nam‐Trung Nguyen, Munkhjargal Bat-Erdene, Eric Campbell, Minh Tam Hoang, Wei-Hsun Chiu, Qin Li, Hongxia Wang, Yu Lin Zhong, Munkhbayar Batmunkh
{"title":"Large-area phosphorene for stable carbon-based perovskite solar cells","authors":"Purevlkham Myagmarsereejid, Selengesuren Suragtkhuu, Quang Thang Trinh, Tim Gould, Nam‐Trung Nguyen, Munkhjargal Bat-Erdene, Eric Campbell, Minh Tam Hoang, Wei-Hsun Chiu, Qin Li, Hongxia Wang, Yu Lin Zhong, Munkhbayar Batmunkh","doi":"10.1038/s41699-024-00476-7","DOIUrl":"10.1038/s41699-024-00476-7","url":null,"abstract":"Carbon-based perovskite solar cells (c-PSCs) have attracted increasing attention due to their numerous advantages including ease of fabrication, the potential of assembling flexible devices, low manufacturing costs as well as large-scale production. However, c-PSCs suffer from the limited hole extraction and high charge carrier recombination due to the inadequate interface contact between the carbon electrode and perovskite film. Herein, we report the fabrication of planar c-PSCs with high efficiency and excellent stability by employing electrochemically produced large-area phosphorene flakes as a hole-transporting layer (HTL). Large-area phosphorene shows well-aligned band energy levels with the perovskite, and thus led to the efficient hole extraction and the reduced hysteresis behaviour. Consequently, while exhibiting excellent stability under various harsh testing conditions, the devices with phosphorene HTL delivered a power conversion efficiency of over 15% with an open-circuit voltage of 1.082 V, which is the highest reported value for c-PSCs without traditional hole transporting materials to date.","PeriodicalId":19227,"journal":{"name":"npj 2D Materials and Applications","volume":" ","pages":"1-11"},"PeriodicalIF":9.7,"publicationDate":"2024-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41699-024-00476-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141298879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tailored plasmon polariton landscape in graphene/boron nitride patterned heterostructures","authors":"Neven Golenić, Stefano de Gironcoli, Vito Despoja","doi":"10.1038/s41699-024-00469-6","DOIUrl":"10.1038/s41699-024-00469-6","url":null,"abstract":"Surface plasmon polaritons (SPPs), which are electromagnetic modes representing collective oscillations of charge density coupled with photons, have been extensively studied in graphene. This has provided a solid foundation for understanding SPPs in 2D materials. However, the emergence of wafer-transfer techniques has led to the creation of various quasi-2D van der Waals heterostructures, highlighting certain gaps in our understanding of their optical properties in relation to SPPs. To address this, we analyzed electromagnetic modes in graphene/hexagonal-boron-nitride/graphene heterostructures on a dielectric Al2O3 substrate using the full ab initio RPA optical conductivity tensor. Our theoretical model was validated through comparison with recent experiments measuring evanescent in-phase Dirac and out-of-phase acoustic SPP branches. Furthermore, we investigate how the number of plasmon branches and their dispersion are sensitive to variables such as layer count and charge doping. Notably, we demonstrate that patterning of the topmost graphene into nanoribbons provides efficient Umklapp scattering of the bottommost Dirac plasmon polariton (DP) into the radiative region, resulting in the conversion of the DP into a robust infrared-active plasmon. Additionally, we show that the optical activity of the DP and its hybridization with inherent plasmon resonances in graphene nanoribbons are highly sensitive to the doping of both the topmost and bottommost graphene layers. By elucidating these optical characteristics, we aspire to catalyze further advancements and create new opportunities for innovative applications in photonics and optoelectronic integration.","PeriodicalId":19227,"journal":{"name":"npj 2D Materials and Applications","volume":" ","pages":"1-13"},"PeriodicalIF":9.7,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41699-024-00469-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141096493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Myeongjin Jang, Minseol Kim, Sol Lee, Minseok Kwon, Hani Kang, Kihyun Lee, Jinsub Park, Anh Tuan Hoang, Jong-Hyun Ahn, Yangjin Lee, Kwanpyo Kim
{"title":"Controlled epitaxy and patterned growth of one-dimensional crystals via surface treatment of two-dimensional templates","authors":"Myeongjin Jang, Minseol Kim, Sol Lee, Minseok Kwon, Hani Kang, Kihyun Lee, Jinsub Park, Anh Tuan Hoang, Jong-Hyun Ahn, Yangjin Lee, Kwanpyo Kim","doi":"10.1038/s41699-024-00473-w","DOIUrl":"10.1038/s41699-024-00473-w","url":null,"abstract":"Mixed-dimensional van der Waals (vdW) heterostructures offer promising platforms for exploring interesting phenomena and functionalities. To exploit their full potential, precise epitaxial processes and well-defined heterointerfaces between different components are essential. Here, we control the growth of one-dimensional (1D) vdW microwires on hexagonal crystals via plasma treatment of the growth templates. AgCN serves as a model 1D system for examining the dependence of the nucleation and growth parameters on the surface treatment conditions and substrate types. The oxygen-plasma-treated transition metal dichalcogenides form step edges mediated by formation of surface metal oxides, leading to robust AgCN epitaxy with an enhanced nucleation density and low horizontal growth rates. Monte Carlo simulations reproduce the experimentally observed growth behaviors and unveil the crucial growth parameters, such as surface diffusivity. The plasma treatment results in distinct effects on graphite and hexagonal boron nitride templates, which undergo plasma-induced amorphization and deactivation of the AgCN vdW epitaxy. We achieve the selective growth of AgCN microwires on graphite using the deactivated vdW epitaxy. This study offers significant insights into the impact of surface treatment on 1D vdW epitaxy, opening avenues for controlled fabrication of mixed-dimensional vdW heterostructures.","PeriodicalId":19227,"journal":{"name":"npj 2D Materials and Applications","volume":" ","pages":"1-9"},"PeriodicalIF":9.7,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41699-024-00473-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140949331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Daniel S. Schneider, Leonardo Lucchesi, Eros Reato, Zhenyu Wang, Agata Piacentini, Jens Bolten, Damiano Marian, Enrique G. Marin, Aleksandra Radenovic, Zhenxing Wang, Gianluca Fiori, Andras Kis, Giuseppe Iannaccone, Daniel Neumaier, Max C. Lemme
{"title":"CVD graphene contacts for lateral heterostructure MoS2 field effect transistors","authors":"Daniel S. Schneider, Leonardo Lucchesi, Eros Reato, Zhenyu Wang, Agata Piacentini, Jens Bolten, Damiano Marian, Enrique G. Marin, Aleksandra Radenovic, Zhenxing Wang, Gianluca Fiori, Andras Kis, Giuseppe Iannaccone, Daniel Neumaier, Max C. Lemme","doi":"10.1038/s41699-024-00471-y","DOIUrl":"10.1038/s41699-024-00471-y","url":null,"abstract":"Intensive research has been carried out on two-dimensional materials, in particular molybdenum disulfide, towards high-performance field effect transistors for integrated circuits1. Fabricating transistors with ohmic contacts is a challenging task due to the formation of a high Schottky barrier that severely limits the performance of the transistors for real-world applications. Graphene-based heterostructures can be used in addition to, or as a substitute for unsuitable metals. In this paper, we present lateral heterostructure transistors made of scalable chemical vapor-deposited molybdenum disulfide and chemical vapor-deposited graphene achieving a low contact resistances of about 9 kΩ·µm and high on/off current ratios of 108. Furthermore, we also present a theoretical model calibrated on our experiments showing further potential for scaling transistors and contact areas into the few nanometers range and the possibility of a substantial performance enhancement by means of layer optimizations that would make transistors promising for use in future logic integrated circuits.","PeriodicalId":19227,"journal":{"name":"npj 2D Materials and Applications","volume":" ","pages":"1-6"},"PeriodicalIF":9.7,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41699-024-00471-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140907154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dmitry A. Mylnikov, Mikhail A. Kashchenko, Kirill N. Kapralov, Davit A. Ghazaryan, Evgenii E. Vdovin, Sergey V. Morozov, Kostya S. Novoselov, Denis A. Bandurin, Alexander I. Chernov, Dmitry A. Svintsov
{"title":"Infrared photodetection in graphene-based heterostructures: bolometric and thermoelectric effects at the tunneling barrier","authors":"Dmitry A. Mylnikov, Mikhail A. Kashchenko, Kirill N. Kapralov, Davit A. Ghazaryan, Evgenii E. Vdovin, Sergey V. Morozov, Kostya S. Novoselov, Denis A. Bandurin, Alexander I. Chernov, Dmitry A. Svintsov","doi":"10.1038/s41699-024-00470-z","DOIUrl":"10.1038/s41699-024-00470-z","url":null,"abstract":"Graphene/hBN/graphene tunnel devices offer promise as sensitive mid-infrared photodetectors but the microscopic origin underlying the photoresponse in them remains elusive. In this work, we investigated the photocurrent generation in graphene/hBN/graphene tunnel structures with localized defect states under mid-IR illumination. We demonstrate that the photocurrent in these devices is proportional to the second derivative of the tunnel current with respect to the bias voltage, peaking during tunneling through the hBN impurity level. We revealed that the origin of the photocurrent generation lies in the change of the tunneling probability upon radiation-induced electron heating in graphene layers, in agreement with the theoretical model that we developed. Finally, we show that at a finite bias voltage, the photocurrent is proportional to either of the graphene layers heating under the illumination, while at zero bias, it is proportional to the heating difference. Thus, the photocurrent in such devices can be used for accurate measurements of the electronic temperature, providing a convenient alternative to Johnson noise thermometry.","PeriodicalId":19227,"journal":{"name":"npj 2D Materials and Applications","volume":" ","pages":"1-8"},"PeriodicalIF":9.7,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41699-024-00470-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140881240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Prosun Santra, Sadegh Ghaderzadeh, Mahdi Ghorbani-Asl, Hannu-Pekka Komsa, Elena Besley, Arkady V. Krasheninnikov
{"title":"Strain-modulated defect engineering of two-dimensional materials","authors":"Prosun Santra, Sadegh Ghaderzadeh, Mahdi Ghorbani-Asl, Hannu-Pekka Komsa, Elena Besley, Arkady V. Krasheninnikov","doi":"10.1038/s41699-024-00472-x","DOIUrl":"10.1038/s41699-024-00472-x","url":null,"abstract":"Strain- and defect-engineering are two powerful approaches to tailor the opto-electronic properties of two-dimensional (2D) materials, but the relationship between applied mechanical strain and behavior of defects in these systems remains elusive. Using first-principles calculations, we study the response to external strain of h-BN, graphene, MoSe2, and phosphorene, four archetypal 2D materials, which contain substitutional impurities. We find that the formation energy of the defect structures can either increase or decrease with bi-axial strain, tensile or compressive, depending on the atomic radius of the impurity atom, which can be larger or smaller than that of the host atom. Analysis of the strain maps indicates that this behavior is associated with the compressive or tensile local strains produced by the impurities that interfere with the external strain. We further show that the change in the defect formation energy is related to the change in elastic moduli of the 2D materials upon introduction of impurity, which can correspondingly increase or decrease. The discovered trends are consistent across all studied 2D materials and are likely to be general. Our findings open up opportunities for combined strain- and defect-engineering to tailor the opto-electronic properties of 2D materials, and specifically, the location and properties of single-photon emitters.","PeriodicalId":19227,"journal":{"name":"npj 2D Materials and Applications","volume":" ","pages":"1-9"},"PeriodicalIF":9.7,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41699-024-00472-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140844997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tunable magnetic confinement effect in a magnetic superlattice of graphene","authors":"Onur Tosun, Preetha Sarkar, Chang Qian, Matthew Gilbert, Qian Chen, Nadya Mason","doi":"10.1038/s41699-024-00468-7","DOIUrl":"10.1038/s41699-024-00468-7","url":null,"abstract":"Two-dimensional van der Waals materials such as graphene present an opportunity for band structure engineering using custom superlattice potentials. In this study, we demonstrate how self-assemblies of magnetic iron-oxide (Fe3O4) nanospheres stacked on monolayer graphene generate a proximity-induced magnetic superlattice in graphene and modify its band structure. Interactions between the nanospheres and the graphene layer generate superlattice Dirac points in addition to a gapped energy spectrum near the K and K′ valleys, resulting in magnetic confinement of quasiparticles around the nanospheres. This is evidenced by gate-dependent resistance oscillations, observed in our low temperature transport measurements, and confirmed by self-consistent tight binding calculations. Furthermore, we show that an external magnetic field can tune the magnetic superlattice potential created by the nanospheres, and thus the transport characteristics of the system. This technique for magnetic-field-tuned band structure engineering using magnetic nanostructures can be extended to a broader class of 2D van der Waals and topological materials.","PeriodicalId":19227,"journal":{"name":"npj 2D Materials and Applications","volume":" ","pages":"1-9"},"PeriodicalIF":9.7,"publicationDate":"2024-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41699-024-00468-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140544581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Exploration of the two-dimensional transition metal phosphide MoP2 as anode for Na/K ion batteries","authors":"Junjie Jin, Udo Schwingenschlögl","doi":"10.1038/s41699-024-00453-0","DOIUrl":"10.1038/s41699-024-00453-0","url":null,"abstract":"Transition metal phosphides are regarded to be potential anode materials for alkali metal ion batteries with abundant availability of the constituent elements. However, the volume changes and resulting structure deterioration during the charge-discharge process are challenges. Using evolutionary search combined with ab initio calculations, we discover a dynamically, thermally, and mechanically stable MoP2 monolayer, which turns out to be an excellent anode material for Na-ion batteries providing a high specific capacity of 339 mA h g−1, low diffusion barrier of 0.12 eV, and low open-circuit voltage of 0.48 V. The volume expansion (125%) is found to be decisively smaller than in the case of black phosphorus (443%), for example.","PeriodicalId":19227,"journal":{"name":"npj 2D Materials and Applications","volume":" ","pages":"1-8"},"PeriodicalIF":9.7,"publicationDate":"2024-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41699-024-00453-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140351732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Riju Pal, Buddhadeb Pal, Suchanda Mondal, Rajesh O. Sharma, Tanmoy Das, Prabhat Mandal, Atindra Nath Pal
{"title":"Spin-reorientation driven emergent phases and unconventional magnetotransport in quasi-2D vdW ferromagnet Fe4GeTe2","authors":"Riju Pal, Buddhadeb Pal, Suchanda Mondal, Rajesh O. Sharma, Tanmoy Das, Prabhat Mandal, Atindra Nath Pal","doi":"10.1038/s41699-024-00463-y","DOIUrl":"10.1038/s41699-024-00463-y","url":null,"abstract":"Non-trivial spin textures driven by strong exchange interaction, magneto-crystalline anisotropy, and electron correlation in a low-dimensional magnetic material often lead to unusual electronic transitions. Through a combination of transport experiments in exfoliated nanoflakes down to 16 layers and first principle calculations, we unravel emergent electronic phases in quasi-2D van der Waals ferromagnet, Fe4GeTe2, possessing ferromagnetic TC ~ 270 K, along with a spin-reorientation transition (TSR ~ 120 K) with the change of magnetic easy axis. Two electronic transitions are identified. The first transition near TSR exhibits a sharp fall in resistivity, followed by a sign change in the ordinary Hall coefficient (R0), together with, maximum negative magnetoresistance (MR) and anomalous Hall conductivity. Another unusual electronic transition, hitherto unknown, is observed near ~ 40–50 K (TQ), where R0 again changes sign and below which, the resistivity shows a quadratic temperature dependence, and MR becomes positive. An analysis of the experimental data further uncovers the role of competing inelastic scattering processes in anomalous magnetotransport behavior. The density-functional theory based first-principle calculations unveil two possible magnetic phases, followed by a low-energy model Hamiltonian which captures the essence of these phases as well as explains the observed magnetotransport behavior. Thus, we demonstrate an interplay between magnetism and band topology and its consequence on electron transport in Fe4GeTe2, important for spintronic applications.","PeriodicalId":19227,"journal":{"name":"npj 2D Materials and Applications","volume":" ","pages":"1-11"},"PeriodicalIF":9.7,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41699-024-00463-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140348884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Huijun Kim, Juhwan Park, Hanggyo Jung, Changho Ra, Jongwook Jeon
{"title":"Logic-in-memory application of ferroelectric-based WS2-channel field-effect transistors for improved area and energy efficiency","authors":"Huijun Kim, Juhwan Park, Hanggyo Jung, Changho Ra, Jongwook Jeon","doi":"10.1038/s41699-024-00466-9","DOIUrl":"10.1038/s41699-024-00466-9","url":null,"abstract":"In this study, we applied ferroelectrics to the gate stack of Field Effect Transistors (FETs) with a 2D transition-metal dichalcogenide (TMDC) channel, actively researching for sub-2nm technology node implementation. Subsequently, we analyzed the circuit characteristics of Logic-in-Memory (LiM) operation and utilized LiM features after applying ferroelectrics to achieve a single-device configuration. Based on well-calibrated simulations, we performed compact modeling in a circuit simulator to depict the temperature-dependent electrical characteristics of ferroelectric FETs with a double gate structure and 2D channel (DG 2D-FeFET) in sub-2nm dimensions. Through this, we have confirmed that the 2D FeFET-based LiM technology, designed for the 2 nm technology node, exhibits superior characteristics in terms of delay, power/energy consumption, and circuit area under all temperature conditions, compared to the conventional CMOS technology based on 2D FETs. This verification serves as proof of the future technological potential of 2D-FeFET in extremely scaled-down technology nodes.","PeriodicalId":19227,"journal":{"name":"npj 2D Materials and Applications","volume":" ","pages":"1-9"},"PeriodicalIF":9.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41699-024-00466-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140333375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}