Article
Chemistry, Multidisciplinary
Wei Zhang, Zhibin Zhao, Min Tan, Adila Adijiang, Shurong Zhong, Xiaona Xu, Tianran Zhao, Emusani Ramya, Lu Sun, Xueyan Zhao, Zhiqiang Fan, Dong Xiang
Summary: The binding orientation of molecules with respect to the electrode is crucial for the performance of molecular devices. However, modulating the binding orientation of single molecules in situ remains challenging. In this study, we demonstrate that the conductance of pyridine-anchored molecular junctions can be controlled by the applied voltage using a STM-BJ technique. Flicker noise measurements and theoretical calculations support the notion that the orientation of nitrogen-gold bonds in the molecular junctions can be manipulated by the mechanical stretching force and electric fields.
Article
Chemistry, Physical
Xingzhou Yang, Songjun Hou, Meiling Su, Qian Zhan, Hanjun Zhang, Sergio M. Quintero, Xiaodong Liu, Junyang Liu, Wenjing Hong, Juan Casado, Qingqing Wu, Colin J. Lambert, Yonghao Zheng
Summary: It is found that the transport properties of a series of fluorene derivatives can be tuned by controlling the degree of localization of certain orbitals, leading to a significant enhancement in conductance. This new understanding of the role of radicals in single-molecule junctions opens up a novel design strategy for single-molecule-based spintronic devices.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Review
Chemistry, Multidisciplinary
William Bro-Jorgensen, Joseph M. Hamill, Rasmus Bro, Gemma C. Solomon
Summary: This tutorial review describes the crucial aspects of applying machine learning to help users avoid common pitfalls. Examples based on single-molecule electron transport experiments demonstrate the application of machine learning and highlight the importance of careful application. The concepts explored are also applicable in other fields with similar data.
CHEMICAL SOCIETY REVIEWS
(2022)
Article
Nanoscience & Nanotechnology
Shintaro Fujii, Enrique Montes, Haruna Cho, Yi Yue, Masaaki Koike, Tomoaki Nishino, Hector Vazquez, Manabu Kiguchi
Summary: In this paper, the tuning of the thermopower of single-molecule junctions of fullerene, 4,4'-bipyridine, and p-phenylenediamine using scanning tunneling microscopy-based break junction technique is demonstrated. The thermoelectric voltage of the junction is tuned by mechanically controlling the tip-electrode separation distance. The atomistic simulations illustrate the shifts in the conduction orbital energies induced by the mechanical compression of the junctions.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Xinlei Yao, Maxime Vonesch, Maiwenn Combes, Jean Weiss, Xiaonan Sun, Jean-Christophe Lacroix
Summary: This study demonstrates the preparation of highly stable single-molecule junctions using diazonium grafting approach. The conductance of porphyrin oligomers is relatively efficient and influenced by the presence of cobalt center, showing a long stability around 10 seconds. Random telegraph signals easily record on/off states of SMJs, indicating the potential applications of this approach in constructing stable molecular junctions.
Article
Multidisciplinary Sciences
Zhuang Yan, Xingxing Li, Yusen Li, Chuangcheng Jia, Na Xin, Peihui Li, Linan Meng, Miao Zhang, Long Chen, Jinlong Yang, Rongming Wang, Xuefeng Guo
Summary: In this study, we demonstrate two configurations of a graphene-porphyrin-graphene single-molecule junction (SMJ) driven by electric field and proton transfer. The transistor configuration shows exceptional field-effect performance with high on/off ratio and gate efficiency. The other configuration reveals controllable proton transfer and tautomerization switching. This work provides insights into constructing multifunctional molecular nanocircuits and understanding the intrinsic properties of matters at the molecular scale.
Article
Multidisciplinary Sciences
Zixiao Wang, Julio L. Palma, Hui Wang, Junzhi Liu, Gang Zhou, M. R. Ajayakumar, Xinliang Feng, Wei Wang, Jens Ulstrup, Alexei A. Kornyshev, Yueqi Li, Nongjian Tao
Summary: Single-molecule electrochemical science has made significant advancements in molecular electronics functions, particularly rectification. This article proposes an experimental and theoretical strategy for in situ rectification in symmetric molecular structures in an electrochemical environment. By independently controlling the electrochemical potential of the tip and substrate electrodes, single-molecule rectification is observed. The polarity and amplitude of the rectification can be tuned by varying the energy and electrolyte concentration. The study provides a promising approach for building controllable single-molecule rectifying devices without the need for asymmetric molecular structures.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Chemistry, Multidisciplinary
Yan Zheng, Ping Duan, Yu Zhou, Chuan Li, Dahai Zhou, Yaping Wang, Li-Chuan Chen, Zhiyu Zhu, Xiaohui Li, Jie Bai, Kai Qu, Tengyang Gao, Jia Shi, Junyang Liu, Qian-Chong Zhang, Zhong-Ning Chen, Wenjing Hong
Summary: Fano resonance in single-molecule junctions is created by interaction between discrete and continuous molecular orbitals, allowing effective modulation of electron transport through interference. Direct observation of Fano resonance has been challenging due to the disappearance of discrete orbitals. Experimental demonstration of Fano resonance in electrochemical gated single-molecule conductance provides insights for designing interference-based electronic devices.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Hector Vazquez
Summary: This method uses density functional theory to calculate the tunneling conductance of single molecule junctions, simplifying the model and reducing computational costs significantly, while also quantifying the relationship between molecular structure and conductance.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Review
Chemistry, Multidisciplinary
Haojie Liu, Hao Zhang, Yongjie Zhao, Junyang Liu, Wenjing Hong
Summary: In the past few decades, prototypes of single-molecule devices have emerged, leading to rapid development in the field of single-molecule electronics. Resolving the interface properties of single-molecule devices is crucial for their various practical applications. This review highlights the significance and urgency of interface resolving at single-molecule junctions (SMJs), summarizes the main progress in the construction, characterization, and modulation of SMJs, and discusses novel functionalization and critical challenges in fabricating reliable molecular devices. It provides a comprehensive understanding of interface resolving and offers novel insights into the design and fabrication of multifunctional molecular devices.
TRENDS IN CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Hang Chen, Yaorong Chen, Hewei Zhang, Wenqiang Cao, Chao Fang, Yicheng Zhou, Zongyuan Xiao, Jia Shi, Wenbo Chen, Junyang Liu, Wenjing Hong
Summary: The study reveals that quantum interference effects can enhance the thermopower of molecular junctions and provide opportunities to manipulate charge transport properties.
CHINESE CHEMICAL LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Shiqiang Zhao, Ze-Ying Deng, Shadiah Albalawi, Qingqing Wu, Lijue Chen, Hewei Zhang, Xin-Jing Zhao, Hao Hou, Songjun Hou, Gang Dong, Yang Yang, Jia Shi, Colin J. Lambert, Yuan-Zhi Tan, Wenjing Hong
Summary: This study fabricates sandwiched single-molecule bilayer-graphene junctions via vdW interactions and investigates their electrical transport properties. The results reveal the importance of the size, layer number, and angle between graphene flake and peripheral groups in determining the cross-plane charge transport through molecular graphene in these junctions.
Article
Chemistry, Physical
Zhi Li, Leopoldo Mejia, Jonathan Marrs, Hyunhak Jeong, Joshua Hihath, Ignacio Franco
Summary: By utilizing atomistic simulations and experiments, researchers have found that even under ideal conditions, molecular junction experiments at the single-molecule level will still exhibit a broad conductance histogram. The dispersion is caused by changes in conductance as the junction is mechanically manipulated and the stochastic nature of junction rupture.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Multidisciplinary
Masnun Naher, David C. Milan, Oday A. Al-Owaedi, Inco J. Planje, Soren Bock, Juan Hurtado-Gallego, Pablo Bastante, Zahra Murtada Abd Dawood, Laura Rincon-Garcia, Gabino Rubio-Bollinger, Simon J. Higgins, Nicolas Agrait, Colin J. Lambert, Richard J. Nichols, Paul J. Low
Summary: The conductance of a series of 12 conjugated molecular wires, including 6 with ruthenium or platinum center, has been determined. The transmission through these wires is mainly through tunneling at the tail of the HOMO resonance near the middle of the HOMO-LUMO gap. The trends in molecular conductance across the series cannot be explained solely by single-parameter models, but require consideration of the complete molecular junction.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Multidisciplinary Sciences
Yu-Ling Zou, Qing-Man Liang, Taige Lu, Yao-Guang Li, Shiqiang Zhao, Jian Gao, Zi-Xian Yang, Anni Feng, Jia Shi, Wenjing Hong, Zhong-Qun Tian, Yang Yang
Summary: Single-molecule electronics enable miniaturization of electronic devices, but current experiments are limited to traditional molecular structures. We developed layer-by-layer single-molecule heterojunctions using single-layer graphene electrodes, called single-molecule two-dimensional van der Waals heterojunctions (M-2D-vdWHs), which can be defined by the thickness of the molecule. By controlling the electric field, we demonstrated reversible switching behavior of the M-2D-vdWHs. These results show that stacked M-2D-vdWHs, composed of single-layer 2D materials and a single molecule, can respond to electric field stimulus, offering potential for unprecedentedly small single-molecule devices.
Review
Chemistry, Multidisciplinary
Ferdinand Evers, Amnon Aharony, Nir Bar-Gill, Ora Entin-Wohlman, Per Hedegard, Oded Hod, Pavel Jelinek, Grzegorz Kamieniarz, Mikhail Lemeshko, Karen Michaeli, Vladimiro Mujica, Ron Naaman, Yossi Paltiel, Sivan Refaely-Abramson, Oren Tal, Jos Thijssen, Michael Thoss, Jan M. van Ruitenbeek, Latha Venkataraman, David H. Waldeck, Binghai Yan, Leeor Kronik
Summary: This article provides a critical overview of the theory of the chirality-induced spin selectivity (CISS) effect and reviews its applications in electron processes. It discusses the latest developments in the understanding of the CISS effects in electron transmission, electron transport, and chemical reactions, and identifies the remaining challenges and research opportunities.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Physical
Asmat Ullah, Keun Hyeong Park, Hieu Dinh Nguyen, Yasir Siddique, S. F. A. Shah, Huyen Tran, Sunghyeok Park, Seok In Lee, Kyung-Koo Lee, Chi-Hwan Han, Kihwan Kim, SeJin Ahn, Inyoung Jeong, Young S. Park, Sungjun Hong
Summary: Recent advancements in perovskite solar cells have shown improvements in performance through enhanced interfacial engineering and charge selective contacts. A novel phenothiazine-based self-assembled monolayer has been introduced as a hole-selective contact, demonstrating significantly improved charge extraction/transport and device stability, leading to high power conversion efficiencies and exceptional operational stability.
ADVANCED ENERGY MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Angela L. Paoletta, E-Dean Fung, Latha Venkataraman
Summary: In this study, Au tunnel junctions are used to simultaneously probe electroluminescence and conductance. It is found that plasmonic enhancement increases with decreasing gap size for junctions biased between 1.4 and 1.8 V, while above 1.9 V, plasmonic enhancement decreases due to quenching caused by tunneling, which is consistent with trends observed for high energy plasmons in scattering experiments.
Article
Chemistry, Multidisciplinary
Woojung Lee, Shayan Louie, Austin M. Evans, Nicholas M. Orchanian, Ilana B. Stone, Boyuan Zhang, Yujing Wei, Xavier Roy, Colin Nuckolls, Latha Venkataraman
Summary: This study demonstrates that dynamic molecular structures lead to temperature-dependent conductance in molecular wires. Thermally activated dihedral rotations increase the probability of molecular wires being in a planar conformation, enhancing tunneling probability. Longer molecular wires with more rotational pivot points exhibit larger temperature dependence on conductance.
Article
Chemistry, Multidisciplinary
Liang Li, Jonathan Z. Low, Jan Wilhelm, Guanming Liao, Suman Gunasekaran, Claudia R. Prindle, Rachel L. Starr, Dorothea Golze, Colin Nuckolls, Michael L. Steigerwald, Ferdinand Evers, Luis M. Campos, Xiaodong Yin, Latha Venkataraman
Summary: A family of oligophenylene-bridged bis(triarylamines) with tunable and stable mono- or di-radicaloid character was studied, showing reversed conductance decay with increasing length for oxidized wires, indicating non-classical quasi-metallic behavior.
Article
Chemistry, Multidisciplinary
Asmat Ullah, Keun Hyeong Park, YoungWan Lee, Sujung Park, Abdullah Bin Faheem, Hieu Dinh Nguyen, Yasir Siddique, Kyung-Koo Lee, Yimhyun Jo, Chi-Hwan Han, SeJin Ahn, Inyoung Jeong, Shinuk Cho, BongSoo Kim, Young S. Park, Sungjun Hong
Summary: Inverted perovskite solar cells offer advantages such as easy processing and high stability, but face challenges in achieving high power conversion efficiency. This study introduces excellent hole-selective materials for inverted PSCs and demonstrates the potential of engineered self-assembled monolayers (SAMs) in achieving high-performance solar cells. The Se-containing SAM shows the strongest interaction with the perovskite absorber and achieves a PCE of 22.73%.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Physical
Liang Li, Suman Gunasekaran, Yujing Wei, Colin Nuckolls, Latha Venkataraman
Summary: This study investigates the conductance properties of 1D TIs such as polyacetylene using a tight-binding approach and discovers the phenomenon of reversed conductance decay in the short chain limit. The impact of edge states on the transmission of single-molecule junctions is analyzed to explain this conductance trend, and methods for tuning the self-energy and on-site energy of edge sites to create longer wires with reversed conductance decays are proposed.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Liang Li, Shayan Louie, Austin M. Evans, Elena Meirzadeh, Colin Nuckolls, Latha Venkataraman
Summary: Molecular one-dimensional topological insulators (1D TIs) that conduct through low-lying topological edge states have potential for nanoelectronic devices. To observe these effects at longer lengths, we design topological oligo[n]emeraldine wires using short 1D TIs as building blocks. As the wire length increases, the number of topological states increases, enabling increased electronic transmission. The longest oligo[7]emeraldine with doped topological states has over 106 enhancements in transmission compared to its pristine form.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Yujing Wei, Liang Li, Julia E. Greenwald, Latha Venkataraman
Summary: Understanding the relationship between molecular geometry and electronic properties of single-molecule junctions is challenging. In this study, we investigated this relationship by applying a sinusoidal modulation to the molecular junction electrode position. We found that junctions formed with molecules having different molecule-electrode interfaces exhibited statistically distinguishable Fourier-transformed conductances. Our findings suggest that voltage-modulated van der Waals interactions play a significant role in the conductance of single-molecule junctions.
Article
Chemistry, Physical
Daniel J. Jackson, Brian A. Dawes, Maria Kamenetska
Summary: Single molecule force spectroscopy using optical tweezers has been successful in measuring dynamic biological processes, but not in synthetic molecular mechanisms. In this study, we demonstrate the trapping of gold nanoparticles in both aqueous and organic conditions using a custom optical tweezers and darkfield instrument, allowing simultaneous measurement of the force and scattering spectra of single gold nanoparticles. Our findings reveal that standard trapping models developed for aqueous conditions cannot explain the observed trends in different media. We also determine that higher pushing forces can mitigate the trapping force increase in higher index organic solvents and lead to axial displacement of the particle, which can be controlled through trap intensity. This work establishes a new model framework incorporating axial forces for understanding nanoparticle dynamics in an optical trap, and proves the effectiveness of the combined darkfield optical tweezers with gold nanoparticles as a probe for single molecule and single particle spectroscopy experiments, with nanoscale control over particle location.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Zhu Liang, Matthew R. Carbone, Wei Chen, Fanchen Meng, Eli Stavitski, Deyu Lu, Mark S. Hybertsen, Xiaohui Qu
Summary: A semisupervised machine learning method called RankAAE is developed and demonstrated for interpreting XANES spectra and discovering structure-spectrum relationships. The method constructs a one-to-one mapping between individual structure descriptors and spectral trends. It provides a robust and quantitative measure of the structure-spectrum relationship, decoupling intertwined spectral contributions from multiple structural characteristics.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Seonghwa Jeong, Eunji Park, Jiyeon Kim, Seok Bae Park, Sung Hoon Kim, Wonyoung Choe, Joonghan Kim, Young S. Park
Summary: This study reports the synthesis and characterization of a B2N2 anthracene derivative with continuous multiple BN units, which exhibits significant variations in bond length and energy gap compared to its all-carbon analogue. The findings may facilitate the development of larger acenes with multiple BN units and potential applications in organic electronics.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Xiaoyun Pan, Katherine Matthews, Brent Lawson, Maria Kamenetska
Summary: This study investigates the conductance and intramolecular hydrogen bonding of histamine using single-molecule conductance measurements and DFT calculations. The results show that histamine in the free-base form can bridge through a molecular structure with intramolecular hydrogen bonding, resulting in higher conductance than through the saturated aliphatic linker. Flicker noise analysis confirms the transport through hydrogen bonding and provides a benchmark for noise measurements in hydrogen-bonded junctions.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Physics, Multidisciplinary
Animesh Ghose, Mikhail Segal, Fanchen Meng, Zhu Liang, Mark S. Hybertsen, Xiaohui Qu, Eli Stavitski, Shinjae Yoo, Deyu Lu, Matthew R. Carbone
Summary: The importance of uncertainty quantification in machine learning methods applied to physical sciences has been highlighted. In this study, neural network ensembles are used to predict x-ray absorption spectra and their uncertainties for small molecules. The performance of the model demonstrates a quantitative correlation between errors and uncertainty estimates. This uncertainty-aware model has the capability to indicate out-of-sample predictions, allowing for integration with large-scale sampling and structure refinement techniques.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Zexin Jin, Qian Cheng, Austin M. Evans, Jesse Gray, Ruiwen Zhang, Si Tong Bao, Fengkai Wei, Latha Venkataraman, Yuan Yang, Colin Nuckolls
Summary: In this study, a modular approach was developed to construct pi-conjugated RA-2DPs with high electrical conductivity and high ion diffusion rates. These materials functioned as organic cathode materials with good rate performance and excellent cycling stability. Importantly, the improved design allowed for higher mass-loadings, enabling practical applications.
