Article
Chemistry, Multidisciplinary
Khadiza Ali, Laura Fernandez, Mohammad A. Kherelden, Anna A. Makarova, Igor Pis, Federica Bondino, James Lawrence, Dimas G. de Oteyza, Dmitry Yu. Usachov, Denis V. Vyalikh, F. Javier Garcia de Abajo, Zakaria M. Abd El-Fattah, J. Enrique Ortega, Frederik Schiller
Summary: This study demonstrates a method for synthesizing nanostriped hBN with periodic texture on Rh surfaces, which is achieved for the first time by imprinting lateral patterns from a one-dimensional template. The electronic structure reveals nanoscale periodic modulation, creating an effective multi-stripe semiconductor structure.
Article
Chemistry, Multidisciplinary
Pin-Chiao Huang, Hongye Sun, Mamun Sarker, Christopher M. Caroff, Gregory S. Girolami, Alexander Sinitskii, Joseph W. Lyding
Summary: This paper demonstrates the fabrication of nanometer-scale metal contacts on individual graphene nanoribbons (GNRs) and the use of these contacts to control the electronic character of the GNRs. Using a low-voltage direct-write STM-based process, sub-5 nm metallic hafnium diboride (HfB2) contacts are patterned directly on top of single GNRs in an ultrahigh-vacuum scanning tunneling microscope (UHV-STM), with all the fabrication performed on a technologically relevant semiconductor silicon substrate. Scanning tunneling spectroscopy (STS) data verify the expected metallic and semiconducting character of the contacts and GNR, and also show induced band bending and p-n junction formation in the GNR due to the metal-GNR work function difference. Contact engineering with different work function metals eliminates the need for complex chemical doping to create GNRs with different characteristics. This paper demonstrates the successful fabrication of precise metal contacts and local p-n junction formation on single GNRs.
Article
Chemistry, Physical
Qing Yuan, Yafei Li, Deping Guo, Cancan Lou, Xingxia Cui, Guangqiang Mei, Chengxiang Jiao, Kai Huang, Xuefeng Hou, Wei Ji, Limin Cao, Min Feng
Summary: This study reports the emergence of a large energy gap in Bi(110) two-atomic-layer nanoribbons grown on a SnSe(001) substrate, which is normally semimetal-like. The size of the energy gap is determined by the Bi coverage, with it disappearing above a certain percentage. Measurements and simulations reveal the distorted black phosphorous structure of both insulating and semimetal-like Bi(110). The experimental strategy can be applied to create Bi(110) nanostructures with unique properties on other surfaces as well.
Article
Chemistry, Multidisciplinary
Maria Tenorio, Cesar Moreno, Pol Febrer, Jesus Castro-Esteban, Pablo Ordejon, Diego Pena, Miguel Pruneda, Aitor Mugarza
Summary: A synthetic strategy to fabricate nanometer scale, coherent lateral superlattice heterojunctions with atomically sharp band discontinuity is reported. By merging interdigitated arrays of different types of graphene nanoribbons, superlattices with chemical heterogeneity and nanoporous structures are obtained.
ADVANCED MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
D. S. Rosenzweig, M. N. L. Hansemann, M. Schnedler, Ph. Ebert, H. Eisele
Summary: The initial stages of hydrogen adsorption on GaAs(110) surfaces at room temperature are investigated using atomically resolved scanning tunneling microscopy and spectroscopy. Two effects are found to occur simultaneously: surface phase separation and formation of hydrogen-induced point defects.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Thais Chagas, Guilherme A. S. Ribeiro, Barbara L. T. Rosa, Danial Bahrami, Arman Davtyan, Rafael R. Barreto, Juan C. Gonzalez, Rogerio Magalhaes-Paniago, Angelo Malachias
Summary: In this study, the researchers investigated the structural and electronic properties of Mg-doped GaAs(111) nanowires, revealing conducting Ga2Mg/Mg clusters on the lateral surfaces, enabling electrical contacts with reduced Schottky barriers. Density functional theory was used to investigate the electronic response of Ga2Mg, showing metallic behavior at room temperature and quantum confinement at low temperatures.
ACS APPLIED NANO MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Matthew B. Donnelly, Mushita M. Munia, Joris G. Keizer, Yousun Chung, A. M. Saffat-Ee Huq, Edyta N. Osika, Yu-Ling Hsueh, Rajib Rahman, Michelle Y. Simmons
Summary: Controlling electron tunneling is crucial in the design and operation of semiconductor nanostructures, especially in quantum computing devices. This study successfully combines scanning tunneling microscopy lithography and tight-binding non-equilibrium Green's function (TB-NEGF) modeling to accurately describe the dependence of tunnel junction resistance on junction length, achieving satisfactory results. The use of TB-NEGF formalism in accurately modeling highly doped, atomically precise tunnel junctions in silicon is confirmed, and this model has potential for improving device performance at the nanoscale.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Review
Chemistry, Multidisciplinary
Xu Liu, Xiao Cai, Yan Zhu
Summary: Bimetallic nanocluster catalysts show potential in tailoring catalytic activity and selectivity. Constructing ideal bimetallic catalysts is challenging due to multiple factors convoluted in the overall catalytic performance. Recent research focuses on the synergistic effects of surface/subsurface heteroatoms and core heteroatoms, providing valuable insights into intraparticle synergism and guiding the development of high-performance catalysts for industrial applications.
ACCOUNTS OF CHEMICAL RESEARCH
(2023)
Article
Nanoscience & Nanotechnology
Pierre Capiod, Maaike van der Sluijs, Jeroen de Boer, Christophe Delerue, Ingmar Swart, Daniel Vanmaekelbergh
Summary: The study utilized rock-salt lead selenide nanocrystals as building blocks for large scale square superlattices, revealing that the electronic structure is still influenced by disorder and variability despite crystalline connections.
Scanning Tunneling Spectroscopy measurements of local density of states and controlled annealing of the sample allowed for imaging of a clean structure and reproducible probing of band gap and electronic states.
Article
Chemistry, Multidisciplinary
Site Li, Anantha Venkataraman Nagarajan, Dominic R. Alfonso, Mingkang Sun, Douglas R. Kauffman, Giannis Mpourmpakis, Rongchao Jin
Summary: In this study, the surface modification of gold nanoclusters by Cd doping was found to significantly enhance the selectivity and activity for CO2 reduction reaction. The Cd-doped Au19Cd2 NC exhibited the highest CO2RR activity reported. Density-functional theory calculations revealed that Cd doping can boost the CO2RR performance by providing energetically feasible pathways and reducing the energy barrier for CO formation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Physics, Multidisciplinary
Wei Chen, YaJun Yan, MingQiang Ren, Tong Zhang, DongLai Feng
Summary: We demonstrate that a self-assembled phase of potassium-doped single-layer para-sexiphenyl film on a gold substrate is a suitable platform for studying the two-impurity Kondo model. The Kondo resonance peak, located close to the Fermi energy, is observed on the isolated K-doped PSP molecules, and splits when another K-doped PSP molecule is present nearby. The splitting of the peak increases with decreasing intermolecular distance without any signs of phase transition.
SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
(2022)
Article
Chemistry, Physical
Remy Pawlak, Ernst Meyer, Khalid N. Anindya, Toshiki Shimizu, Jung-Ching Liu, Takumi Sakamaki, Rui Shang, Alain Rochefort, Eiichi Nakamura
Summary: The substitution of heteroatoms and non-benzenoid carbons in nanographene structure allows for atomic engineering of electronic properties. This study demonstrates the bottom-up synthesis of graphene nanoribbons with embedded BN-doped rubicene components using on-surface chemistry. The incorporation of BN heteroatoms results in an increased electronic band gap, providing opportunities for designing semiconducting graphene nanoribbons with optoelectronic properties.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Hyo Won Kim, Insu Jeon, Wonhee Ko, Seong Heon Kim
Summary: The anisotropic twofold symmetry of Ge(110) makes it unique for single-crystalline graphene growth. Growth of graphene on Ge(110) surface initiates unidirectionally from carbon cluster seeds, forming graphene nanoribbons (GNRs) that eventually transform into graphene nanoislands (GNIs) and coalesce into single crystalline monolayer graphene. STS measurements reveal GNRs with small bandgaps, induced by graphene confinement effect, providing insights into growth mechanism of graphene on Ge(110) surface under various synthesis conditions.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Physical
Nataly Herrera-Reinoza, Alisson Ceccatto dos Santos, Luis Henrique de Lima, Richard Landers, Abner de Siervo
Summary: This study reports the successful growth of h-BNC from an unexplored single molecular precursor on Ir(111), and discusses the conformation structure of the monolayer and its correlation with the local electronic properties. The results show that h-BNC structure can be described as BN-doped graphene with specific electronic properties.
CHEMISTRY OF MATERIALS
(2021)
Article
Nanoscience & Nanotechnology
Hyo Won Kim, Won-Jae Joo, Won-Jun Jang, Seong Heon
Summary: This study investigates the electronic properties of pseudo-GNRs in large-scale graphene sheets grown on Ge(110) using low temperature scanning tunneling microscopy and spectroscopy. The pseudo-GNRs are found to be aligned in a specific direction and form metallic-semiconducting-metallic junction structures with the surrounding graphene area.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2023)
Article
Engineering, Electrical & Electronic
Nesli Yagmurcukardes, Abdullah Bayram, Hasan Aydin, Mehmet Yagmurcukardes, Yaser Acikbas, Francois M. Peeters, Cem Celebi
Summary: The sensitivity of graphene-based sensors to ammonia was improved by etching, and the etched sensors showed higher resistance to humidity.
IEEE SENSORS JOURNAL
(2022)
Article
Engineering, Electrical & Electronic
Senne Fransen, Kherim Willems, Harold Philipsen, Devin Verreck, Willem Van Roy, Olivier Y. F. Henry, Antonio Arreghini, Geert Van den Bosch, Arnaud Furnemont, Maarten Rosmeulen
Summary: In this paper, a storage memory device based on the electro-deposition and electrodissolution of multilayered metal stacks in deep nanometer-sized wells is proposed, which enables bit densities of >1 Tbit/mm(2). It addresses the challenge of bit density scaling slowdown expected for 3-D NAND flash beyond 2030 and provides a proof-of-principle demonstration of the write/read mechanism on millimeter- and micrometer-sized electrodes, showing the device's potential for reaching very high bit densities. Simple analytical expressions based on finite element simulations are derived to evaluate the response time scaling for nanometer-sized electrodes in the envisioned device.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Nanoscience & Nanotechnology
Amanda H. Trout, Seth W. Kurfman, Yueguang Shi, Michael Chilcote, Michael E. Flatte, Ezekiel Johnston-Halperin, David W. McComb
Summary: This study focuses on a molecule-based ferrimagnetic semiconductor and investigates its electronic structure and structural ordering using density functional theory and various experimental techniques. The study reveals the robust magnetic ordering mechanism and degradation pathways of the material.
Article
Nanoscience & Nanotechnology
Ogulcan Acikgoz, Enrique Guerrero, Alper Yanilmaz, Omur E. Dagdeviren, Cem Celebi, David A. Strubbe, Mehmet Z. Baykara
Summary: In this study, atomic force microscopy was used to measure the friction on Re-doped MoS2. Unlike the common observation of decreasing friction with increasing number of layers in two-dimensional materials, Re-doped MoS2 exhibits friction that is inversely proportional to the number of layers. Raman spectroscopy measurements and ab initio calculations reveal that this phenomenon is related to Re intercalation, with an increase in out-of-plane stiffness inversely correlating with the number of layers as the physical mechanism behind this remarkable observation, revealing a distinctive regime of puckering for 2D materials.
Article
Nanoscience & Nanotechnology
Stan E. T. ter Huurne, Adonai Rodrigues Da Cruz, Niels van Hoof, Rasmus H. Godiksen, Sara A. Elrafei, Alberto G. Curto, Michael E. Flatte, Jaime Gomez Rivas
Summary: By using THz near-field spectroscopy, time-resolved THz measurements were conducted on a single nanolayered crystal. This technique allows for the investigation of the relation between carrier dynamics and phonon transport in nanolayered crystals.
ACS APPLIED NANO MATERIALS
(2022)
Article
Chemistry, Analytical
Pieter Berden, Rodrigo S. Wiederkehr, Liesbet Lagae, Jan Michiels, Tim Stakenborg, Maarten Fauvart, Willem Van Roy
Summary: We developed an analytical model that explains the relationship between amplification efficiency, template accessibility, and rain in dPCR assays. Through Monte Carlo simulations, we found that reduced amplification efficiency leads to broader threshold cycle distributions, while template inaccessibility results in an exponential tail rain pattern.
ANALYTICAL CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Sybren Santermans, Geert Hellings, Marc Heyns, Willem Van Roy, Koen Martens
Summary: Electrolyte-gated silicon FETs have the potential to detect single molecules, benefiting the development of high-throughput molecular sensing chips in genomics or proteomics. However, the sensitivity of these FETs to charges near the gate oxide is strongly reduced by electrolyte screening. We found that nano-scaling all FET channel dimensions is necessary to achieve a sufficiently large single-molecule SNR. In our study, a suspended nanowire FET architecture with specific dimensions showed the highest SNR of about 10 for DNA detection in an electrolyte solution.
Article
Chemistry, Multidisciplinary
Sarah M. Thompson, Cuneyt Sahin, Shengsong Yang, Michael E. Flatte, Christopher B. Murray, Lee C. Bassett, Cherie R. Kagan
Summary: Copper-doped zinc sulfide (ZnS:Cu) is a versatile phosphor material that exhibits down-conversion luminescence in various regions of the electromagnetic spectrum. Colloidal nanocrystals (NCs) of ZnS:Cu are of particular interest for quantum information science due to their precise control over size, composition, and surface chemistry. The researchers propose a method for synthesizing ZnS:Cu NCs that primarily emit red light, and they explore the thermodynamic stability and electronic structure of the CuZn-VS complex. The understanding of the emission dynamics and controlled synthesis of CuZn-VS in ZnS NCs will contribute to the development of quantum point defects in this material.
Article
Engineering, Electrical & Electronic
Nesli Yagmurcukardes, Abdullah Bayram, Hasan Aydin, Mustafa Can, Serafettin Demic, Yaser Acikbas, Cem Celebi
Summary: In this study, the NH3 sensing capabilities of graphene films were improved by modifying self-assembled monolayers. The modified graphene films showed a two-fold increase in NH3 uptake compared to the unmodified films. This suggests that self-assembled monolayers can enhance NH3 adsorption and improve the detection response.
IEEE SENSORS JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Ala K. Jehad, Mehmet Fidan, Ozhan Unverdi, Cem Celebi
Summary: A self-powered, high-performance graphene/Silicon Carbide ultraviolet photodetector was fabricated, and the effect of using monolayer and bilayer graphene on device performance parameters was investigated. The photodetector exhibited high spectral responsivity, maximum detectivity, and minimum noise equivalent power. Bilayer graphene showed no significant change in spectral responsivity but improved the response speed compared to monolayer graphene.
SENSORS AND ACTUATORS A-PHYSICAL
(2023)
Article
Engineering, Electrical & Electronic
Alper Yanilmaz, Ozhan Unverdi, Cem Celebi
Summary: The study aims to reduce optical crosstalk and improve device performance by integrating graphene with silicon. The results show that using monolayer graphene as a separate electrode on the SOI substrate can greatly minimize optical crosstalk between neighboring elements. This research is expected to have significant implications in various technological applications such as multi-wavelength light measurement, level metering, high-speed photometry, and position/motion detection.
SENSORS AND ACTUATORS A-PHYSICAL
(2023)
Article
Chemistry, Physical
Emine Karagoz, Cigdem Tuc Altaf, Ecenaz Yaman, Ipek Deniz Yildirim, Emre Erdem, Cem Celebi, Mehmet Fidan, Mehmet Sankir, Nurdan Demirci Sankir
Summary: This study examines the performance of a metal/semiconductor/metal-type flexible photodetector made from pristine and manganese doped ZnO nanorods. The results show that increasing the concentration of zinc precursor improves the detectivity and responsivity of the photodetectors. Additionally, manganese doping further enhances the detectivity and responsivity of the photodetectors. This research demonstrates the ability to create high-performance flexible photodetectors even with low concentrations of zinc precursor.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Physics, Multidisciplinary
Adonai R. da Cruz, Michael E. Flatte
Summary: Theoretical calculations predict the anisotropic dissipationless circulating current induced by a spin defect in a two-dimensional electron gas. The shape and spatial extent of these dissipationless circulating currents depend dramatically on the relative strengths of spin-orbit fields with differing spatial symmetry, offering the potential to use an electric gate to manipulate nanoscale magnetic fields and couple magnetic defects. The spatial structure of the magnetic field produced by this current is calculated and provides a direct way to measure the spin-orbit fields of the host, as well as the defect spin orientation, e.g., through scanning nanoscale magnetometry.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
N. J. Harmon, M. E. Flatte
Summary: A pure spin current can be controlled by an external magnetic field and a linearly inhomogeneous spin-only field under specific conditions. This phenomenon can be validated through classical models and optical experiments.
Article
Engineering, Electrical & Electronic
Senne Fransen, Kherim Willems, Harold Philipsen, Devin Verreck, Willem Van Roy, Olivier Y. F. Henry, Antonio Arreghini, Geert Van den Bosch, Arnaud Furnemont, Maarten Rosmeulen
Summary: The proposed storage memory device achieves high bit densities through electro-deposition and electrodissolution in deep nanometer-sized wells, addressing the challenge of bit density scaling slowdown in future 3-D NAND flash. Experimental results on millimeter- and micrometer-sized electrodes demonstrate the device's potential for achieving very high bit densities.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
