1
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Jacobse PH, Sarker M, Saxena A, Zahl P, Wang Z, Berger E, Aluru NR, Sinitskii A, Crommie MF. Tunable Magnetic Coupling in Graphene Nanoribbon Quantum Dots. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2400473. [PMID: 38412424 DOI: 10.1002/smll.202400473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Indexed: 02/29/2024]
Abstract
Carbon-based quantum dots (QDs) enable flexible manipulation of electronic behavior at the nanoscale, but controlling their magnetic properties requires atomically precise structural control. While magnetism is observed in organic molecules and graphene nanoribbons (GNRs), GNR precursors enabling bottom-up fabrication of QDs with various spin ground states have not yet been reported. Here the development of a new GNR precursor that results in magnetic QD structures embedded in semiconducting GNRs is reported. Inserting one such molecule into the GNR backbone and graphitizing it results in a QD region hosting one unpaired electron. QDs composed of two precursor molecules exhibit nonmagnetic, antiferromagnetic, or antiferromagnetic ground states, depending on the structural details that determine the coupling behavior of the spins originating from each molecule. The synthesis of these QDs and the emergence of localized states are demonstrated through high-resolution atomic force microscopy (HR-AFM), scanning tunneling microscopy (STM) imaging, and spectroscopy, and the relationship between QD atomic structure and magnetic properties is uncovered. GNR QDs provide a useful platform for controlling the spin-degree of freedom in carbon-based nanostructures.
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Affiliation(s)
- Peter H Jacobse
- Department of Physics, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Mamun Sarker
- Department of Chemistry, University of Nebraska, Lincoln, NE, 68588, USA
- Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Anshul Saxena
- Walker Department of Mechanical Engineering, University of Texas, Austin, TX, 78712, USA
- Oden Institute for Computational Engineering and Sciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - Percy Zahl
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Ziyi Wang
- Department of Physics, University of California, Berkeley, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Kavli Energy NanoSciences Institute at the University of California Berkeley and the Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Emma Berger
- Department of Physics, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Narayana R Aluru
- Walker Department of Mechanical Engineering, University of Texas, Austin, TX, 78712, USA
- Oden Institute for Computational Engineering and Sciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - Alexander Sinitskii
- Department of Chemistry, University of Nebraska, Lincoln, NE, 68588, USA
- Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Michael F Crommie
- Department of Physics, University of California, Berkeley, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Kavli Energy NanoSciences Institute at the University of California Berkeley and the Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
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2
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Kuo DMT. Charge transport through the multiple end zigzag edge states of armchair graphene nanoribbons and heterojunctions. RSC Adv 2024; 14:20113-20119. [PMID: 38915325 PMCID: PMC11194785 DOI: 10.1039/d4ra02574a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Accepted: 06/18/2024] [Indexed: 06/26/2024] Open
Abstract
This comprehensive study investigates charge transport through the multiple end zigzag edge states of finite-size armchair graphene nanoribbons/boron nitride nanoribbons (n-AGNR/w-BNNR) junctions under a longitudinal electric field, where n and w denote the widths of the AGNRs and the BNNRs, respectively. In 13-atom wide AGNR segments, the edge states exhibit a blue Stark shift in response to the electric field, with only the long decay length zigzag edge states showing significant interaction with the red Stark shift subband states. Charge tunneling through such edge states assisted by the subband states is elucidated in the spectra of the transmission coefficient. In the 13-AGNR/6-BNNR heterojunction, notable influences on the energy levels of the end zigzag edge states of 13-AGNRs induced by BNNR segments are observed. We demonstrate the modulation of these energy levels in resonant tunneling situations, as depicted by bias-dependent transmission coefficient spectra. Intriguing nonthermal broadening of tunneling current shows a significant peak-to-valley ratio. Our findings highlight the promising potential of n-AGNR/w-BNNR heterojunctions with long decay length edge states in the realm of GNR-based single electron transistors at room temperature.
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Affiliation(s)
- David M T Kuo
- Department of Electrical Engineering, Department of Physics, National Central University Chungli 32001 Taiwan
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3
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Louis E, Chiappe G, Vergés JA, San-Fabián E. Long-Range Effects in Topologically Defective Arm-Chair Graphene Nanoribbons. NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:778. [PMID: 38727373 PMCID: PMC11085075 DOI: 10.3390/nano14090778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 04/26/2024] [Accepted: 04/27/2024] [Indexed: 05/13/2024]
Abstract
The electronic structure of 7/9-AGNR superlattices with up to eight unit cells has been studied by means of state-of-the-art Density Functional Theory (DFT) and also by two model Hamiltonians, the first one including only local interactions (Hubbard model, Hu) while the second one is extended to allow long-range Coulomb interactions (Pariser, Parr and Pople model, PPP). Both are solved within mean field approximation. At this approximation level, our calculations show that 7/9 interfaces are better described by spin non-polarized solutions than by spin-polarized wavefunctions. Consequently, both Hu and PPP Hamiltonians lead to electronic structures characterized by a gap at the Fermi level that diminishes as the size of the system increases. DFT results show similar trends although a detailed analysis of the density of states around the Fermi level shows quantitative differences with both Hu and PPP models. Before improving model Hamiltonians, we interpret the electronic structure obtained by DFT in terms of bands of topological states: topological states localized at the system edges and extended bulk topological states that interact between them due to the long-range Coulomb terms of Hamiltonian. After careful analysis of the interaction among topological states, we find that the discrepancy between ab initio and model Hamiltonians can be resolved considering a screened long-range interaction that is implemented by adding an exponential cutoff to the interaction term of the PPP model. In this way, an adjusted cutoff distance λ=2 allows a good recovery of DFT results. In view of this, we conclude that the correct description of the density of states around the Fermi level (Dirac point) needs the inclusion of long-range interactions well beyond the Hubbard model but not completely unscreened as is the case for the PPP model.
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Affiliation(s)
- Enrique Louis
- Departamento de Física Aplicada, Instituto Universitario de Materiales de Alicante (IUMA), Universidad de Alicante, 03080 Alicante, Spain;
| | - Guillermo Chiappe
- Departamento de Física Aplicada, Instituto Universitario de Materiales de Alicante (IUMA), Universidad de Alicante, 03080 Alicante, Spain;
| | - José A. Vergés
- Departamento de Teoría y Simulación de Materiales, Instituto de Ciencia de Materiales de Madrid (CSIC), Cantoblanco, 28049 Madrid, Spain;
| | - Emilio San-Fabián
- Departamento de Química Física, Instituto Universitario de Materiales de Alicante (IUMA), Universidad de Alicante, 03080 Alicante, Spain
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4
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Zhu Z, Lu J, Yuan S, He Y, Zheng F, Jiang H, Yan Y, Sun Q. Automated Generation and Analysis of Molecular Images Using Generative Artificial Intelligence Models. J Phys Chem Lett 2024; 15:1985-1992. [PMID: 38346383 DOI: 10.1021/acs.jpclett.3c03504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
The development of scanning probe microscopy (SPM) has enabled unprecedented scientific discoveries through high-resolution imaging. Simulations and theoretical analysis of SPM images are equally important as obtaining experimental images since their comparisons provide fruitful understandings of the structures and physical properties of the investigated systems. So far, SPM image simulations are conventionally based on quantum mechanical theories, which can take several days in tasks of large-scale systems. Here, we have developed a scanning tunneling microscopy (STM) molecular image simulation and analysis framework based on a generative adversarial model, CycleGAN. It allows efficient translations between STM data and molecular models. Our CycleGAN-based framework introduces an approach for high-fidelity STM image simulation, outperforming traditional quantum mechanical methods in efficiency and accuracy. We envision that the integration of generative networks and high-resolution molecular imaging opens avenues in materials discovery relying on SPM technologies.
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Affiliation(s)
- Zhiwen Zhu
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Jiayi Lu
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Shaoxuan Yuan
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Yu He
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Fengru Zheng
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Hao Jiang
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Yuyi Yan
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Qiang Sun
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
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5
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Kuo DMT. Thermoelectric properties of armchair graphene nanoribbons with array characteristics. RSC Adv 2024; 14:3513-3518. [PMID: 38259995 PMCID: PMC10801832 DOI: 10.1039/d3ra07863a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 01/17/2024] [Indexed: 01/24/2024] Open
Abstract
The thermoelectric properties of armchair graphene nanoribbons (AGNRs) with array characteristics are investigated theoretically using the tight-binding model and Green's function technique. The AGNR structures with array characteristics are created by embedding a narrow boron nitride nanoribbon (BNNR) into a wider AGNR, resulting in two narrow AGNRs. This system is denoted as w-AGNR/n-BNNR, where 'w' and 'n' represent the widths of the wider AGNR and narrow BNNR, respectively. We elucidate the coupling effect between two narrow symmetrical AGNRs on the electronic structure of w-AGNR/i-BNNR. A notable discovery is that the power factor of the 15-AGNR/5-BNNR with the minimum width surpasses the quantum limitation of power factor for 1D ideal systems. The energy level degeneracy observed in the first subbands of w-AGNR/n-BNNR structures proves to be highly advantageous in enhancing the electrical power outputs of graphene nanoribbon devices.
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Affiliation(s)
- David M T Kuo
- Department of Electrical Engineering and Department of Physics, National Central University Chungli 32001 Taiwan
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6
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Jiang H, He Y, Lu J, Zheng F, Zhu Z, Yan Y, Sun Q. Unraveling the Mechanisms of On-Surface Photoinduced Reaction with Polarized Light Excitations. ACS NANO 2024; 18:1118-1125. [PMID: 38117979 DOI: 10.1021/acsnano.3c10690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
On-surface reaction has been shown as a powerful strategy to achieve atomically precise nanostructures. Numerous reactions have been realized on surfaces with thermal annealing as the primary excitation. In contrast, far fewer reactions have been triggered by light on surfaces despite its advantages due to the nonthermal process. This is possibly ascribed to our limited understanding on the excitation mechanisms of on-surface photoinduced reactions. In this work, we have studied the photoinduced debrominated coupling by using a linearly polarized light. We successfully achieved the reaction with no annealing process and obtained oligomers as the primary reaction products, which is in contrast with the formation of polymers with traditional thermal treatments. By exploring the dependence of reaction yield on the angle of incidence, we demonstrate an experimental method that can provide fundamental insights. The comparison with the theoretical approximation suggests indirect hot carrier excitation as the leading excitation mechanism. Our results not only provide fundamental insight into the surface photochemical reactions but also set the basis for harnessing light to construct unconventional nanomaterials.
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Affiliation(s)
- Hao Jiang
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Yu He
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Jiayi Lu
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Fengru Zheng
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Zhiwen Zhu
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Yuyi Yan
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Qiang Sun
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
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7
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Kuo DMT. Thermal rectification through the topological states of asymmetrical length armchair graphene nanoribbons heterostructures with vacancies. NANOTECHNOLOGY 2023; 34:505401. [PMID: 37703858 DOI: 10.1088/1361-6528/acf93a] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Accepted: 09/12/2023] [Indexed: 09/15/2023]
Abstract
We present a theoretical investigation of electron heat current in asymmetrical length armchair graphene nanoribbon (AGNR) heterostructures with vacancies, focusing on the topological states (TSs). In particular, we examine the 9-7-9 AGNR heterostructures where the TSs are well-isolated from the conduction and valence subbands. This isolation effectively mitigates thermal noise of subbands arising from temperature fluctuations during charge transport. Moreover, when the TSs exhibit an orbital off-set, intriguing electron heat rectification phenomena are observed, primarily attributed to inter-TS electron Coulomb interactions. To enhance the heat rectification ratio (ηQ), we manipulate the coupling strengths between the heat sources and the TSs by introducing asymmetrical lengths in the 9-AGNRs. This approach offers control over the rectification properties, enabling significant enhancements. Additionally, we introduce vacancies strategically positioned between the heat sources and the TSs to suppress phonon heat current. This arrangement effectively reduces the overall phonon heat current, while leaving the TSs unaffected. Our findings provide valuable insights into the behavior of electron heat current in AGNR heterostructures, highlighting the role of topological states, inter-TS electron Coulomb interactions, and the impact of structural modifications such as asymmetrical lengths and vacancy positioning. These results pave the way for the design and optimization of graphene-based devices with improved thermal management and efficient control of electron heat transport.
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Affiliation(s)
- David M T Kuo
- Department of Electrical Engineering and Department of Physics, National Central University, Chungli, 320, Taiwan
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8
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Zheng F, Lu J, Zhu Z, Jiang H, Yan Y, He Y, Yuan S, Sun Q. Predicting Molecular Self-Assembly on Metal Surfaces Using Graph Neural Networks Based on Experimental Data Sets. ACS NANO 2023; 17:17545-17553. [PMID: 37611029 DOI: 10.1021/acsnano.3c06405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Abstract
The application of supramolecular chemistry on solid surfaces has received extensive attention in the past few decades. To date, combining experiments with quantum mechanical or molecular dynamic methods represents the key strategy to explore the molecular self-assembled structures, which is, however, often laborious. Recently, machine learning (ML) has become one of the most exciting tools in material research, allowing for both efficiency and accuracy in predicting molecular properties. In this work, we constructed a graph neural network to predict the self-assembly of functional polycyclic aromatic hydrocarbons (PAHs) on metal surfaces. Using scanning tunneling microscopy (STM), we characterized the self-assembled nanostructures of a homologous series of PAH molecules on different metal surfaces to construct an experimental data set for model training. Compared with traditional ML algorithms, our model exhibits better predictive performance. Finally, the generalization of the model is further verified by comparing the ML predictions and experimental results of different functionalized molecule. Our results demonstrate training experimental data sets to produce a predictive ML model of molecular self-assembly with generalization performance, which allows for the predictive design of nanostructures with functional molecules.
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Affiliation(s)
- Fengru Zheng
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Jiayi Lu
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Zhiwen Zhu
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Hao Jiang
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Yuyi Yan
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Yu He
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Shaoxuan Yuan
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Qiang Sun
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
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9
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Paudel RK, Ren CY, Chang YC. Semi-Empirical Pseudopotential Method for Graphene and Graphene Nanoribbons. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2066. [PMID: 37513077 PMCID: PMC10383570 DOI: 10.3390/nano13142066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/06/2023] [Accepted: 07/11/2023] [Indexed: 07/30/2023]
Abstract
We implemented a semi-empirical pseudopotential (SEP) method for calculating the band structures of graphene and graphene nanoribbons. The basis functions adopted are two-dimensional plane waves multiplied by several B-spline functions along the perpendicular direction. The SEP includes both local and non-local terms, which were parametrized to fit relevant quantities obtained from the first-principles calculations based on the density-functional theory (DFT). With only a handful of parameters, we were able to reproduce the full band structure of graphene obtained by DFT with a negligible difference. Our method is simple to use and much more efficient than the DFT calculation. We then applied this SEP method to calculate the band structures of graphene nanoribbons. By adding a simple correction term to the local pseudopotentials on the edges of the nanoribbon (which mimics the effect caused by edge creation), we again obtained band structures of the armchair nanoribbon fairly close to the results obtained by DFT. Our approach allows the simulation of optical and transport properties of realistic nanodevices made of graphene nanoribbons with very little computation effort.
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Affiliation(s)
- Raj Kumar Paudel
- Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan
- Molecular Science and Technology, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan
- Department of Physics, National Central University, Chungli 320, Taiwan
| | - Chung-Yuan Ren
- Department of Physics, National Kaohsiung Normal University, Kaohsiung 824, Taiwan
| | - Yia-Chung Chang
- Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan
- Department of Physics, National Cheng-Kung University, Tainan 701, Taiwan
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10
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Yuan S, Zhu Z, Lu J, Zheng F, Jiang H, Sun Q. Applying a Deep-Learning-Based Keypoint Detection in Analyzing Surface Nanostructures. Molecules 2023; 28:5387. [PMID: 37513258 PMCID: PMC10384857 DOI: 10.3390/molecules28145387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/09/2023] [Accepted: 07/11/2023] [Indexed: 07/30/2023] Open
Abstract
Scanning tunneling microscopy (STM) imaging has been routinely applied in studying surface nanostructures owing to its capability of acquiring high-resolution molecule-level images of surface nanostructures. However, the image analysis still heavily relies on manual analysis, which is often laborious and lacks uniform criteria. Recently, machine learning has emerged as a powerful tool in material science research for the automatic analysis and processing of image data. In this paper, we propose a method for analyzing molecular STM images using computer vision techniques. We develop a lightweight deep learning framework based on the YOLO algorithm by labeling molecules with its keypoints. Our framework achieves high efficiency while maintaining accuracy, enabling the recognitions of molecules and further statistical analysis. In addition, the usefulness of this model is exemplified by exploring the length of polyphenylene chains fabricated from on-surface synthesis. We foresee that computer vision methods will be frequently used in analyzing image data in the field of surface chemistry.
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Affiliation(s)
- Shaoxuan Yuan
- Materials Genome Institute, Shanghai University, Shanghai 200444, China
| | - Zhiwen Zhu
- Materials Genome Institute, Shanghai University, Shanghai 200444, China
| | - Jiayi Lu
- Materials Genome Institute, Shanghai University, Shanghai 200444, China
| | - Fengru Zheng
- Materials Genome Institute, Shanghai University, Shanghai 200444, China
| | - Hao Jiang
- Materials Genome Institute, Shanghai University, Shanghai 200444, China
| | - Qiang Sun
- Materials Genome Institute, Shanghai University, Shanghai 200444, China
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11
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Kuo DMT. Effects of Coulomb Blockade on the Charge Transport through the Topological States of Finite Armchair Graphene Nanoribbons and Heterostructures. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:nano13111757. [PMID: 37299660 DOI: 10.3390/nano13111757] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 05/26/2023] [Accepted: 05/28/2023] [Indexed: 06/12/2023]
Abstract
In this study, we investigate the charge transport properties of semiconducting armchair graphene nanoribbons (AGNRs) and heterostructures through their topological states (TSs), with a specific focus on the Coulomb blockade region. Our approach employs a two-site Hubbard model that takes into account both intra- and inter-site Coulomb interactions. Using this model, we calculate the electron thermoelectric coefficients and tunneling currents of serially coupled TSs (SCTSs). In the linear response regime, we analyze the electrical conductance (Ge), Seebeck coefficient (S), and electron thermal conductance (κe) of finite AGNRs. Our results reveal that at low temperatures, the Seebeck coefficient is more sensitive to many-body spectra than electrical conductance. Furthermore, we observe that the optimized S at high temperatures is less sensitive to electron Coulomb interactions than Ge and κe. In the nonlinear response regime, we observe a tunneling current with negative differential conductance through the SCTSs of finite AGNRs. This current is generated by electron inter-site Coulomb interactions rather than intra-site Coulomb interactions. Additionally, we observe current rectification behavior in asymmetrical junction systems of SCTSs of AGNRs. Notably, we also uncover the remarkable current rectification behavior of SCTSs of 9-7-9 AGNR heterostructure in the Pauli spin blockade configuration. Overall, our study provides valuable insights into the charge transport properties of TSs in finite AGNRs and heterostructures. We emphasize the importance of considering electron-electron interactions in understanding the behavior of these materials.
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Affiliation(s)
- David M T Kuo
- Department of Electrical Engineering, National Central University, Chungli 320, Taiwan, China
- Department of Physics, National Central University, Chungli 320, Taiwan, China
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12
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Elkodous MA, Olojede SO, Sahoo S, Kumar R. Recent advances in modification of novel carbon-based composites: Synthesis, properties, and biotechnological/ biomedical applications. Chem Biol Interact 2023; 379:110517. [PMID: 37149208 DOI: 10.1016/j.cbi.2023.110517] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 03/12/2023] [Accepted: 04/26/2023] [Indexed: 05/08/2023]
Abstract
Nowadays, carbon-based materials owing to great interest in biomedical science/biotechnology and applied for effective diagnosis and treatment of disease. To enhance the effectiveness of carbon nanotubes (CNTs)/graphene-based materials for bio-medical science/technology applications, different kinds of surface modification/functionalization were developed for the attachment of metal oxides nanostructures, biomolecules and polymers. The attachment of pharmaceutical agents with CNTs/graphene, make it a favorable candidate in research field of bio-medical science/technology applications. Surface modified/functionalized CNTs and graphene derivatives materials integrated with pharmaceutical agents has been developed for the purpose of cancer therapy, antibacterial action, pathogens bio detection, drug and gene delivery. Surface modification or functionalization of CNT/graphene materials provides good platform for pharmaceutical agents attachment with improved surface Raman scattering, fluorescence and its quenching capability. Graphene-based biosensing and bioimaging technologies are widely applied to identify numerous trace level analytes. These fluorescent and electrochemical sensors are utilized primarily for detecting organic, inorganic, and biomolecules. In this article, we highlights and summarized overview of the current research progress concerned on the CNTs/graphene-based materials as a new generation materials for detection and treatment of diseases.
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Affiliation(s)
- M Abd Elkodous
- Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi, 441-8580, Japan; Center for Nanotechnology (CNT), School of Engineering and Applied Sciences, Nile University, Sheikh Zayed, Giza, 16453, Egypt
| | - Samuel Oluwaseun Olojede
- Nanotechnology Platforms, Discipline of Clinical Anatomy, School of Laboratory Medicine & Medical Sciences, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - Sumanta Sahoo
- School of Chemical Engineering, Yeungnam University, 280 Daehak-ro, Gyeongsan, Gyeongbuk, 38541, Republic of Korea.
| | - Rajesh Kumar
- Department of Mechanical Engineering, Indian Institute of Technology, Kanpur, 208016, Uttar Pradesh, India.
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Kuo DMT. Effects of metallic electrodes on the thermoelectric properties of zigzag graphene nanoribbons with periodic vacancies. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2023; 35:305301. [PMID: 37068484 DOI: 10.1088/1361-648x/accdac] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 04/17/2023] [Indexed: 06/19/2023]
Abstract
We theoretically analyze the thermoelectric properties of graphene quantum dot arrays (GQDAs) with line- or surface-contacted metal electrodes. Such GQDAs are realized as zigzag graphene nanoribbons (ZGNRs) with periodic vacancies. Gaps and minibands are formed in these GQDAs, which can have metallic and semiconducting phases. The electronic states of the first conduction (valence) miniband with nonlinear dispersion may have long coherent lengths along the zigzag edge direction. With line-contacted metal electrodes, the GQDAs have the characteristics of serially coupled quantum dots (SCQDs) if the armchair edge atoms of the ZGNRs are coupled to the electrodes. By contrast, the GQDAs have the characteristics of parallel quantum dots if the zigzag edge atoms are coupled to the electrodes. The maximum thermoelectric power factors of SCQDs with line-contacted electrodes of Cu, Au, Pt, Pd, or Ti at room temperature were similar or greater than 0.186 nW K-1; their figures of merit were greater than three. GQDAs with line-contacted metal electrodes have much better thermoelectric performance than surface contacted metal electrodes.
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Affiliation(s)
- David M T Kuo
- Department of Electrical Engineering and Department of Physics, National Central University, Chungli 320, Taiwan
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14
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Feng S, Luo Y, Jiang J, Wang S. Examining the Long-Range Effect in Very Long Graphene Nanoribbons: A First-Principles Study. J Phys Chem Lett 2022; 13:11223-11229. [PMID: 36445836 DOI: 10.1021/acs.jpclett.2c03184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The role of long-range effect on the modulation of the electronic structure of graphene nanoribbons has been little studied due to the limitations of existing theoretical and computational methods. By splitting a molecule top-down and calculating and jointing the Fock matrix of fragments, we developed a computational method suitable for large-size molecules with random doping and arbitrary geometry. Utilizing this method, we achieved the study of the effects of dopants and curvature on graphene nanoribbons (GNRs). It reveals that both dopants and curvature can change the charge distribution of GNRs, while the influence of dopants is more significant and can extend up to 1-3 nm. The electronic excitation properties of GNRs are also largely modified by the doping state or nonuniform curvature. Our findings provide not only a feasible approach for studying the electronic structure of large-size molecules but also the possibility to improve the properties of graphene-based materials by dopants and local curvature.
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Affiliation(s)
- Shuo Feng
- Hefei National Research Center for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, CAS Center for Excellence in Nanoscience, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Yi Luo
- Hefei National Research Center for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, CAS Center for Excellence in Nanoscience, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Jun Jiang
- Hefei National Research Center for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, CAS Center for Excellence in Nanoscience, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Song Wang
- Hefei National Research Center for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, CAS Center for Excellence in Nanoscience, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
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15
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Kuo DMT, Chang YC. Contact Effects on Thermoelectric Properties of Textured Graphene Nanoribbons. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:nano12193357. [PMID: 36234484 PMCID: PMC9565821 DOI: 10.3390/nano12193357] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 09/19/2022] [Accepted: 09/22/2022] [Indexed: 06/12/2023]
Abstract
The transport and thermoelectric properties of finite textured graphene nanoribbons (t-GNRs) connected to electrodes with various coupling strengths are theoretically studied in the framework of the tight-binding model and Green's function approach. Due to quantum constriction induced by the indented edges, such t-GNRs behave as serially coupled graphene quantum dots (SGQDs). These types of SGQDs can be formed by tailoring zigzag GNRs (ZGNRs) or armchair GNRs (AGNRs). Their bandwidths and gaps can be engineered by varying the size of the quantum dot and the neck width at indented edges. Effects of defects and junction contact on the electrical conductance, Seebeck coefficient, and electron thermal conductance of t-GNRs are calculated. When a defect occurs in the interior site of textured ZGNRs (t-ZGNRs), the maximum power factor within the central gap or near the band edges is found to be insensitive to the defect scattering. Furthermore, we found that SGQDs formed by t-ZGNRs have significantly better electrical power outputs than those of textured ANGRs due to the improved functional shape of the transmission coefficient in t-ZGNRs. With a proper design of contact, the maximum power factor (figure of merit) of t-ZGNRs could reach 90% (95%) of the theoretical limit.
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Affiliation(s)
- David M. T. Kuo
- Department of Electrical Engineering and Department of Physics, National Central University, Chungli 320, Taiwan
| | - Yia-Chung Chang
- Research Center for Applied Sciences, Academic Sinica, Taipei 11529, Taiwan
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
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16
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de Oteyza DG, Frederiksen T. Carbon-based nanostructures as a versatile platform for tunable π-magnetism. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:443001. [PMID: 35977474 DOI: 10.1088/1361-648x/ac8a7f] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 08/17/2022] [Indexed: 06/15/2023]
Abstract
Emergence ofπ-magnetism in open-shell nanographenes has been theoretically predicted decades ago but their experimental characterization was elusive due to the strong chemical reactivity that makes their synthesis and stabilization difficult. In recent years, on-surface synthesis under vacuum conditions has provided unprecedented opportunities for atomically precise engineering of nanographenes, which in combination with scanning probe techniques have led to a substantial progress in our capabilities to realize localized electron spin states and to control electron spin interactions at the atomic scale. Here we review the essential concepts and the remarkable advances in the last few years, and outline the versatility of carbon-basedπ-magnetic materials as an interesting platform for applications in spintronics and quantum technologies.
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Affiliation(s)
- Dimas G de Oteyza
- Nanomaterials and Nanotechnology Research Center (CINN), CSIC-UNIOVI-PA, E-33940 El Entrego, Spain
- Donostia International Physics Center (DIPC)-UPV/EHU, E-20018 San Sebastián, Spain
| | - Thomas Frederiksen
- Donostia International Physics Center (DIPC)-UPV/EHU, E-20018 San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, E-48013 Bilbao, Spain
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17
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Lu J, Jiang H, Yan Y, Zhu Z, Zheng F, Sun Q. High-Throughput Preparation of Supramolecular Nanostructures on Metal Surfaces. ACS NANO 2022; 16:13160-13167. [PMID: 35862580 DOI: 10.1021/acsnano.2c06294] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
One of the contemporary challenges in materials science lies in the rapid materials screening and discovery. Experimental sample libraries can be generated by high-throughput parallel synthesis to map the composition space for rapid material discoveries. Molecular self-assembly on surfaces has proved a useful way to construct nanostructures with interesting topologies or properties. Despite the strong dependence of molecular stoichiometry on the structures, high-throughput preparations of supramolecular surface nanostructures have been far less explored. Here, by integrating a physical mask into the standard ultra-high-vacuum (UHV) molecular preparation system we show a high-throughput approach for preparing supramolecular nanostructures of continuous composition spreads on metal surfaces. The spatially addressable sample libraries of supramolecular self-assemblies are characterized by high-resolution scanning probe microscopy. We could explore different binary nanostructures of varying molecular ratios on one single substrate. Moreover, we use the minimum spanning tree approach to qualitatively and quantitatively study the structural properties of the formed nanostructures. This high-throughput approach may accelerate the screening and exploration of surface-supported, low-dimensional nanostructures not limited to supramolecular interactions.
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Affiliation(s)
- Jiayi Lu
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Hao Jiang
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Yuyi Yan
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Zhiwen Zhu
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Fengru Zheng
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
| | - Qiang Sun
- Materials Genome Institute, Shanghai University, 200444 Shanghai, China
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18
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Flores E, Mella JD, Aparicio E, Gonzalez RI, Parra C, Bringa EM, Munoz F. Inducing a topological transition in graphene nanoribbon superlattices by external strain. Phys Chem Chem Phys 2022; 24:7134-7143. [PMID: 35262146 DOI: 10.1039/d2cp00038e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Armchair graphene nanoribbons, when forming a superlattice, can be classified into different topological phases, with or without edge states. By means of tight-binding and classical molecular dynamics (MD) simulations, we studied the electronic and mechanical properties of some of these superlattices. MD shows that fracture in modulated superlattices is brittle, as for unmodulated ribbons, and occurs at the thinner regions, with staggered superlattices achieving a larger fracture strain than inline superlattices. We found a general mechanism to induce a topological transition with strain, related to the electronic properties of each segment of the superlattice, and by studying the sublattice polarization we were able to characterize the transition and the response of these states to the strain. For the cases studied in detail here, the topological transition occurred at ∼3-5% strain, well below the fracture strain. The topological states of the superlattice - if present - are robust to strain even close to fracture. The topological transition was characterized by means of the sublattice polarization of the states.
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Affiliation(s)
- E Flores
- Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile
| | - José D Mella
- Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile
| | - E Aparicio
- CONICET and Universidad de Mendoza, Mendoza, 5500, Argentina
| | - R I Gonzalez
- Centro de Nanotecnología Aplicada, Facultad de Ciencias, Universidad Mayor, Santiago, Chile. .,Centro para el Desarrollo de la Nanociencia y la Nanotecnología, CEDENNA, Santiago, Chile
| | - C Parra
- Laboratorio de Nanobiomateriales, Departamento de Física, Universidad Técnica Federico Santa María, Valparaiso, Chile.
| | - E M Bringa
- CONICET and Universidad de Mendoza, Mendoza, 5500, Argentina.,Centro de Nanotecnología Aplicada, Facultad de Ciencias, Universidad Mayor, Santiago, Chile.
| | - F Munoz
- Centro para el Desarrollo de la Nanociencia y la Nanotecnología, CEDENNA, Santiago, Chile.,Departamento de Física, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
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19
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Zhou Z, Fernández‐García JM, Zhu Y, Evans PJ, Rodríguez R, Crassous J, Wei Z, Fernández I, Petrukhina MA, Martín N. Site‐Specific Reduction‐Induced Hydrogenation of a Helical Bilayer Nanographene with K and Rb Metals: Electron Multiaddition and Selective Rb
+
Complexation. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202115747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Zheng Zhou
- Department of Chemistry University at Albany State University of New York Albany NY 12222 USA
- School of Materials Science and Engineering Tongji University 4800 Cao'an Road Shanghai 201804 China
| | - Jesús M. Fernández‐García
- Departamento de Química Orgánica I Facultad de Ciencias Químicas Universidad Complutense de Madrid Ciudad Universitaria s/n 28040 Madrid Spain
| | - Yikun Zhu
- Department of Chemistry University at Albany State University of New York Albany NY 12222 USA
| | - Paul J. Evans
- Departamento de Química Orgánica I Facultad de Ciencias Químicas Universidad Complutense de Madrid Ciudad Universitaria s/n 28040 Madrid Spain
| | - Rafael Rodríguez
- Institut des Sciences Chimiques de Rennes UMR 6226 CNRS—Univ. Rennes Campus de Beaulieu 35042 Rennes Cedex France
| | - Jeanne Crassous
- Institut des Sciences Chimiques de Rennes UMR 6226 CNRS—Univ. Rennes Campus de Beaulieu 35042 Rennes Cedex France
| | - Zheng Wei
- Department of Chemistry University at Albany State University of New York Albany NY 12222 USA
| | - Israel Fernández
- Departamento de Química Orgánica I Facultad de Ciencias Químicas Universidad Complutense de Madrid Ciudad Universitaria s/n 28040 Madrid Spain
| | - Marina A. Petrukhina
- Department of Chemistry University at Albany State University of New York Albany NY 12222 USA
| | - Nazario Martín
- Departamento de Química Orgánica I Facultad de Ciencias Químicas Universidad Complutense de Madrid Ciudad Universitaria s/n 28040 Madrid Spain
- IMDEA-Nanociencia Campus de la Universidad Autónoma de Madrid C/Faraday, 9 28049 Madrid Spain
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20
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Zhou Z, Fernández-García JM, Zhu Y, Evans PJ, Rodríguez R, Crassous J, Wei Z, Fernández I, Petrukhina MA, Martín N. Site-Specific Reduction-Induced Hydrogenation of a Helical Bilayer Nanographene with K and Rb Metals: Electron Multiaddition and Selective Rb + Complexation. Angew Chem Int Ed Engl 2021; 61:e202115747. [PMID: 34875130 PMCID: PMC9300088 DOI: 10.1002/anie.202115747] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Indexed: 01/01/2023]
Abstract
The chemical reduction of π‐conjugated bilayer nanographene 1 (C138H120) with K and Rb in the presence of 18‐crown‐6 affords [K+(18‐crown‐6)(THF)2][{K+(18‐crown‐6)}2(THF)0.5][C138H1223−] (2) and [Rb+(18‐crown‐6)2][{Rb+(18‐crown‐6)}2(C138H1223−)] (3). Whereas K+ cations are fully solvent‐separated from the trianionic core thus affording a “naked” 1.3− anion, Rb+ cations are coordinated to the negatively charged layers of 1.3−. According to DFT calculations, the localization of the first two electrons in the helicene moiety leads to an unprecedented site‐specific hydrogenation process at the carbon atoms located on the edge of the helicene backbone. This uncommon reduction‐induced site‐specific hydrogenation provokes dramatic changes in the (electronic) structure of 1 as the helicene backbone becomes more compressed and twisted upon chemical reduction, which results in a clear slippage of the bilayers.
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Affiliation(s)
- Zheng Zhou
- Department of Chemistry, University at Albany, State University of New York, Albany, NY 12222, USA.,School of Materials Science and Engineering, Tongji University, 4800 Cao'an Road, Shanghai, 201804, China
| | - Jesús M Fernández-García
- Departamento de Química Orgánica I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Yikun Zhu
- Department of Chemistry, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Paul J Evans
- Departamento de Química Orgánica I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Rafael Rodríguez
- Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Univ. Rennes, Campus de Beaulieu, 35042, Rennes Cedex, France
| | - Jeanne Crassous
- Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Univ. Rennes, Campus de Beaulieu, 35042, Rennes Cedex, France
| | - Zheng Wei
- Department of Chemistry, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Israel Fernández
- Departamento de Química Orgánica I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Marina A Petrukhina
- Department of Chemistry, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Nazario Martín
- Departamento de Química Orgánica I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain.,IMDEA-Nanociencia, Campus de la Universidad Autónoma de Madrid, C/Faraday, 9, 28049, Madrid, Spain
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