Article
Chemistry, Physical
Erika Rajackaite, Domantas Peckus, Rimantas Gudaitis, Tomas Tamulevicius, Sarunas Meskinis, Sigitas Tamulevicius
Summary: This study investigated the growth of vertical graphene nanosheets (VGN) with various heights and densities on fused silica substrates using microwave plasma-enhanced chemical vapor deposition technique. The research focused on the evolution of VGN properties with different growth durations and found a correlation between TAS results and the defectiveness and disorder of VGN layers. Optimal growth conditions were determined with increasing deposition duration, ensuring high-quality graphene deposition. Further increase in deposition time resulted in the formation of different carbon allotropes.
SURFACES AND INTERFACES
(2021)
Article
Materials Science, Multidisciplinary
A. P. Yelisseyev, A. A. Emelyanov, A. K. Rebrov, N. Timoshenko, I. B. Yudin, S. A. Gromilov, A. T. Titov, M. Yu Plotnikov
Summary: Diamond coatings were obtained on a molybdenum substrate through gas-phase deposition, with the formation of nuclei and their growth and competition being key steps. The study of coating morphology revealed the growth and deposition process of particles in the gas phase, while XRD and Raman spectroscopy analysis identified the structure and composition of the coatings.
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
(2021)
Article
Chemistry, Physical
Hyungsub Lim, Hyo Chan Lee, Kilwon Cho
Summary: Graphene/Cu composites show promise as future electrode materials due to their mechanical, electrical, and thermal stability. However, the presence of graphene accelerates oxidation of the underlying Cu surface, which affects the properties of the composites. Therefore, it is critical to investigate the effects of Cu oxidation on the interfacial properties of graphene/Cu composites.
Article
Chemistry, Physical
P. Vinchon, X. Glad, G. Robert Bigras, R. Martel, L. Stafford
Summary: Hyperspectral Raman imaging is used to visualize defects in polycrystalline graphene under ion bombardment, showing zero-dimensional and one-dimensional defects in grains and at grain boundaries, respectively, and preferential self-healing at the grain boundaries.
Article
Nanoscience & Nanotechnology
Fangzhu Xiong, Fengsong Qian, Jie Sun, Weiling Guo, Longfei Li, Yiyang Xie, Zaifa Du, Yibo Dong, Le Wang, Chen Xu
Summary: Vertical graphene thin films are successfully grown on SiO2/Si substrates using plasma-enhanced chemical vapor deposition. The function of plasma in the growth process is clarified, and the results can provide insights for the growth of other vertical two-dimensional materials. The scalable and transfer-free nature of the vertical graphene films makes them promising for optoelectronic applications.
Article
Engineering, Electrical & Electronic
Carsten Strobel, Carlos A. Chavarin, Sandra Voelkel, Andreas Jahn, Andre Hiess, Martin Knaut, Matthias Albert, Christian Wenger, Olaff Steinke, Ulf Stephan, Soeren Roehlecke, Thomas Mikolajick
Summary: The arrival of high-mobility two-dimensional materials like graphene has brought back the vertical semiconductor-metal-semiconductor (SMS) hot electron transistors. With the monolayer thickness of graphene, improved SMS transistors with a semimetallic graphene-base electrode are now possible for high-frequency applications. In this study, a device composed of amorphous silicon, graphene, and crystalline silicon is reported. The device is fabricated by a four-mask lithography process for the first time, leading to significant improvements in device performance. A strongly increased common-emitter current gain of 2% has been achieved, while the on-off ratio improved to 1.6 x 105, surpassing theoretical predictions. Better interface characteristics and decreased lateral dimensions of the devices were the main contributing factors. Based on DC measurements, a cutoff frequency of approximately 26 MHz is expected.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Na Li, Di Li, Zhen Zhen, Rujing Zhang, Rende Mu, Zhenhua Xu, Limin He
Summary: Temperature is a crucial factor in the synthesis of graphene by chemical vapor deposition. This study investigates the nucleation and growth of graphene at different temperatures using plasma-enhanced chemical vapor deposition. The results show that graphene nucleation and growth vary significantly in different temperature zones, with different growth forms observed in different temperature regions. The study proposes models to explain the nucleation and growth of graphene in these temperature zones.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Zhichen Yan, Shuangyue Wang, Xianjue Chen, Geedhika K. Poduval, John A. Stride
Summary: Chemical vapor deposition (CVD) shows great potential in large-scale production of graphene films. A new method has been developed to directly grow graphene films on crystalline silicon wafers with a 300 nm oxide layer using a seeded-CVD growth approach. The use of methane as feedstock and optimized graphene seeds has improved the film formation, which consists of graphene layers formed by the coalescence of expanding graphene seeds according to SEM, X-ray photoelectron and Raman spectroscopies. The films also exhibit regions of single graphene crystallites resulting from lateral growth of the seeds. Moreover, the unilateral conductivity of the graphene films suggests potential application in device fabrication due to the presence of graphene nanoribbons.
JOURNAL OF MATERIALS SCIENCE
(2023)
Article
Physics, Condensed Matter
Domantas Peckus, Rimantas Gudaitis, Erika Rajackaite, Marjan Monshi, Sarunas Meskinis, Sigitas Tamulevicius
Summary: Vertical graphene nanosheets (VGN) were prepared using a microwave plasma-enhanced chemical vapor deposition technique on glass and fused silica. The quality of VGN was explored through Raman scattering spectroscopy and transient absorption spectroscopy (TAS), showing a correlation between Raman scattering spectroscopy data and TAS parameters. The ability to prepare high-quality VGN on glass at low substrate price makes it attractive for practical applications.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Chemistry, Multidisciplinary
Noelia Rubio, Heather Au, Gabriel O. Coulter, Laure Guetaz, Gerard Gebel, Cecilia Mattevi, Milo S. P. Shaffer
Summary: The study shows that the locus of functionalisation on graphene-related materials and the progress of the reaction strongly depend on the starting feedstock. Experiments with five characteristically different graphite sources reveal an increase in grafting ratio and an improvement in grafting stoichiometry as flake radius decreases. Raman spectrum imaging indicates that grafting is directed towards flake edges.
Article
Chemistry, Physical
Giuliana Faggio, Rossella Grillo, Nicola Lisi, Francesco Buonocore, Rosa Chierchia, Min Jung Kim, Gwan-Hyoung Lee, Andrea Capasso, Giacomo Messina
Summary: In this study, ultrasensitive graphene substrates were developed using ethanol Chemical Vapor Deposition (CVD), capable of detecting trace amounts of molecules down to extremely low concentrations. This exceptional result is attributed to two main features: more efficient charge transfer and a large number of grain boundaries that act as trapping sites for the molecules.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Andreas Tsiamis, Francisco Diaz Sanchez, Niklas Hartikainen, Michael Chung, Srinjoy Mitra, Ying Chin Lim, Huey Ling Tan, Norbert Radacsi
Summary: This study presents a scalable method for developing ultrasensitive electrochemical biosensors by maximizing sensor conductivity through graphene wrapping of carbonized electrospun nanofibers. The effectiveness of the graphene wrap was determined visually and chemically, with the graphene-wrapped carbonized nanofiber electrode showing significantly improved performance. Despite inhibitive effects from the carbon glue used, the graphene-wrapped carbonized nanofibers exhibited potential for a highly conductive and inert sensing platform.
Article
Chemistry, Physical
Damjan Ivekovic, Sunil Kumar, Andrea Gajovic, Tihana Cizmar, Marko Karlusic
Summary: High-energy heavy ion irradiation is an effective method for nanostructuring 2D materials by introducing controlled defects. It is particularly attractive for mass production of graphene nanomembranes, as nanopore size and density can be easily adjusted through ion irradiation parameters. Understanding the mechanisms of nanopore formation due to high-energy heavy ion impact is crucial. In this study, Raman spectroscopy was used to examine the response of bilayer and trilayer graphene to irradiation. Analysis of spectra obtained from various ion beams revealed that damage production efficiency is strongly correlated with nuclear energy loss and the contribution of electronic energy loss to damage formation is minimal.
Article
Chemistry, Physical
Longkun Que, Jianping Ai, Taihuan Shao, Ruipeng Han, Junhua Su, Yifan Guo, Yifan Liu, Jinyang Li, Xian Jian, Zuowan Zhou
Summary: Designing large-area and high-quality graphene and its derivatives for surface-enhanced Raman scattering (SERS) is crucial for achieving high sensitivity and stability. However, the efficient preparation and regulation of such structures present significant challenges. In this study, fluorinated graphene (fGE) was developed for high-performance SERS through a simple process of fluorination. By controlling the nucleation density of graphene growth with NH3-plasma assistance, large-area graphene (GE) was obtained and then reacted with fluorocarbon to produce fGE. The resulting fGE films showed exceptional molecular SERS sensitivity for Rhodamine 6G (R6G) with a limit as low as 10-9 mol/L.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Meitong Nie, Yuming Zhao, Wonil Nam, Junyeob Song, Wenqi Zhu, Henri J. Lezec, Amit Agrawal, Wei Zhou
Summary: The research introduces nanolaminate plasmonic nanocavities on 3D vertical nanopillar arrays for broadband SERS operation with large enhancement factors. It shows uniform SERS performance and demonstrates nanoscale broadband SERS operation at the single MIM nanocavity level. Numerical studies reveal that the nanolaminate plasmonic nanocavities can support multiple hybridized plasmonic modes for concentrating optical fields across a broadband wavelength range.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Chung Hee Moon, Marzieh Tousi, Joseph Cheeney, Tam-Triet Ngo-Duc, Zheng Zuo, Jianlin Liu, Elaine D. Haberer
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2015)
Article
Chemistry, Multidisciplinary
Tam-Triet Ngo-Duc, Joshua M. Plank, Gongde Chen, Reed E. S. Harrison, Dimitrios Morikis, Haizhou Liu, Elaine D. Haberer
Article
Nanoscience & Nanotechnology
Jesus M. Velazquez, Sivapalan Baskaran, Anil V. Gaikwad, Tam-Triet Ngo-Duc, Xiangtong He, Michael M. Oye, M. Meyyappan, Tapan K. Rout, John Y. Fu, Sarbajit Banerjee
ACS APPLIED MATERIALS & INTERFACES
(2013)
Article
Physics, Applied
Tam-Triet Ngo-Duc, Jovi Gacusan, Nobuhiko P. Kobayashi, Mohan Sanghadasa, M. Meyyappan, Michael M. Oye
APPLIED PHYSICS LETTERS
(2013)
Article
Chemistry, Physical
Lars Dugaiczyk, Tam-Triet Ngo-Duc, Jovi Gacusan, Karandeep Singh, Jonathan Yang, Sarnath Santhanam, Jin-Woo Han, Jessica E. Koehne, Nobuhiko P. Kobayashi, M. Meyyappan, Michael M. Oye
CHEMICAL PHYSICS LETTERS
(2013)
Article
Nanoscience & Nanotechnology
Tam Ngo-Duc, Karandeep Singh, M. Meyyappan, Michael M. Oye
Article
Nanoscience & Nanotechnology
Tam-Triet Ngo-Duc, Zaira Alibay, Joshua M. Plank, Joseph Earl Cheeney, Elaine D. Haberer
ACS APPLIED MATERIALS & INTERFACES
(2020)
Article
Nanoscience & Nanotechnology
Joshua M. Plank, Zaira Alibay, Tam-Triet Ngo-Duc, Michelle Lai, Eleanor A. S. Mayes, Elaine D. Haberer
ACS APPLIED NANO MATERIALS
(2020)
Proceedings Paper
Nanoscience & Nanotechnology
Tam-Triet Ngo-Duc, Mohammed Shahriar Zaman, Chung-Hee Moon, Elaine D. Haberer
NANOBIOSYSTEMS: PROCESSING, CHARACTERIZATION, AND APPLICATIONS VII
(2014)