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Chan YKS, Affendi YA, Ang PO, Baria-Rodriguez MV, Chen CA, Chui APY, Giyanto, Glue M, Huang H, Kuo CY, Kim SW, Lam VYY, Lane DJW, Lian JS, Lin SMNN, Lunn Z, Nañola CL, Nguyen VL, Park HS, Suharsono, Sutthacheep M, Vo ST, Vibol O, Waheed Z, Yamano H, Yeemin T, Yong E, Kimura T, Tun K, Chou LM, Huang D. Decadal stability in coral cover could mask hidden changes on reefs in the East Asian Seas. Commun Biol 2023; 6:630. [PMID: 37301948 PMCID: PMC10257672 DOI: 10.1038/s42003-023-05000-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 05/31/2023] [Indexed: 06/12/2023] Open
Abstract
Coral reefs in the Central Indo-Pacific region comprise some of the most diverse and yet threatened marine habitats. While reef monitoring has grown throughout the region in recent years, studies of coral reef benthic cover remain limited in spatial and temporal scales. Here, we analysed 24,365 reef surveys performed over 37 years at 1972 sites throughout East Asia by the Global Coral Reef Monitoring Network using Bayesian approaches. Our results show that overall coral cover at surveyed reefs has not declined as suggested in previous studies and compared to reef regions like the Caribbean. Concurrently, macroalgal cover has not increased, with no indications of phase shifts from coral to macroalgal dominance on reefs. Yet, models incorporating socio-economic and environmental variables reveal negative associations of coral cover with coastal urbanisation and sea surface temperature. The diversity of reef assemblages may have mitigated cover declines thus far, but climate change could threaten reef resilience. We recommend prioritisation of regionally coordinated, locally collaborative long-term studies for better contextualisation of monitoring data and analyses, which are essential for achieving reef conservation goals.
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Affiliation(s)
- Y K S Chan
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore.
| | - Y A Affendi
- Institute of Ocean and Earth Sciences, Universiti Malaya, Kuala Lumpur, Malaysia
| | - P O Ang
- Institute of Space and Earth Information Science, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - M V Baria-Rodriguez
- Marine Science Institute, University of the Philippines Diliman, Quezon, Philippines
| | - C A Chen
- Biodiversity Research Centre, Academia Sinica, Taipei, Taiwan
| | - A P Y Chui
- Institute of Space and Earth Information Science, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Giyanto
- Research Center for Oceanography, National Research and Innovation Agency (BRIN), Jakarta, Indonesia
| | - M Glue
- Fauna & Flora International, Phnom Penh, Cambodia
| | - H Huang
- South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - C-Y Kuo
- Biodiversity Research Centre, Academia Sinica, Taipei, Taiwan
| | - S W Kim
- School of Biological Sciences, The University of Queensland, Brisbane, Australia
| | - V Y Y Lam
- Global Coral Reef Monitoring Network, International Union for the Conservation of Nature, Washington D.C., USA
- Marine Spatial Ecology Lab, School of Biological Sciences, The University of Queensland, Brisbane, Australia
| | - D J W Lane
- Lee Kong Chian Natural History Museum, National University of Singapore, Singapore, Singapore
- Universiti Brunei Darussalam, Bandar Seri Begawan, Brunei Darussalam
| | - J S Lian
- South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - S M N N Lin
- Fauna & Flora International, Yangon, Myanmar
| | - Z Lunn
- Fauna & Flora International, Yangon, Myanmar
| | - C L Nañola
- University of the Philippines Mindanao, Davao, Philippines
| | - V L Nguyen
- Institute of Oceanography, Vietnam Academy of Science and Technology, Nha Trang, Vietnam
| | - H S Park
- Korean Institute of Ocean Science and Technology, Seoul, South Korea
| | - Suharsono
- Research Center for Oceanography, National Research and Innovation Agency (BRIN), Jakarta, Indonesia
| | - M Sutthacheep
- Department of Biological Sciences, Ramkhamhaeng University, Bangkok, Thailand
| | - S T Vo
- Institute of Oceanography, Vietnam Academy of Science and Technology, Nha Trang, Vietnam
| | - O Vibol
- Department of Fisheries Conservation, Ministry of Agriculture, Phnom Penh, Cambodia
| | - Z Waheed
- Borneo Marine Research Institute, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - H Yamano
- National Institute for Environmental Studies, Tsukaba, Japan
| | - T Yeemin
- Faculty of Science, Ramkhamhaeng University, Bangkok, Thailand
| | - E Yong
- Reef Check Brunei, Bandar Seri Begawan, Brunei Darussalam
| | - T Kimura
- Global Coral Reef Monitoring Network East Asia Region, Tokyo, Japan
- Palau International Coral Reef Center, Koror, Palau
| | - K Tun
- Global Coral Reef Monitoring Network East Asia Region, Tokyo, Japan
- National Biodiversity Centre, National Parks Board, Singapore, Singapore
| | - L M Chou
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- Tropical Marine Science Institute, National University of Singapore, Singapore, Singapore
| | - D Huang
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- Lee Kong Chian Natural History Museum, National University of Singapore, Singapore, Singapore
- Tropical Marine Science Institute, National University of Singapore, Singapore, Singapore
- Centre for Nature-based Climate Solutions, National University of Singapore, Singapore, Singapore
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Nguyen TT, Chiu CH, Lin CY, Chiu NC, Chen PY, Le TTV, Le DN, Duong AH, Nguyen VL, Huynh TN, Truong HK, Phan TL, Nguyen TTT, Shih SR, Huang CG, Weng YJ, Hsieh EF, Chang S, Chen C, Tai IC, Huang LM. Efficacy, safety, and immunogenicity of an inactivated, adjuvanted enterovirus 71 vaccine in infants and children: a multiregion, double-blind, randomised, placebo-controlled, phase 3 trial. Lancet 2022; 399:1708-1717. [PMID: 35427481 DOI: 10.1016/s0140-6736(22)00313-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/28/2022] [Accepted: 02/01/2022] [Indexed: 01/25/2023]
Abstract
BACKGROUND Children are susceptible to severe or fatal enterovirus 71 (EV71) infections. We aimed to evaluate the efficacy, safety, and immunogenicity of EV71vac, an aluminium phosphate-adjuvanted inactivated EV71 vaccine in children aged 2-71 months. METHODS We did a randomised, double-blinded, placebo-controlled, phase 3 trial at five hospitals in Taiwan and two in Vietnam. Children aged 2-71 months were stratified by country and age, and randomly assigned (1:1) to receive two doses of EV71vac or placebo via intramuscular injection 56 days apart. Children aged 2-23 months received a third booster dose on day 366. The primary endpoint was the clinical efficacy of the total vaccinated cohort against EV71-associated diseases during the follow-up period, from 14 days after the second dose to when 15 cases of EV71 infections were confirmed in the per-protocol population. Our safety analysis included all participants who received at least one dose of EV71vac. This trial is registered with ClinicalTrials.gov, NCT03865238, and is complete. FINDINGS Between April 23 and Dec 25, 2019, of 3663 children assessed, 3061 were randomly assigned, of whom 3049 were vaccinated: 1521 children in the EV71vac group and 1528 in the placebo group. By May 20, 2021, our primary efficacy analysis included 2959 children, with 1476 children in the EV71vac group and 1483 children in the placebo group. The vaccine efficacy of EV71vac was 96·8% (95% CI 85·5-100) against EV71 associated diseases (p<0·0001). The percentage of participants who reported solicited adverse events were similar in both groups: 865 (56·9%) in the EV71vac group and 852 (55·8%) in the placebo group. Almost all reported solicited adverse events were mild and self-limited. INTERPRETATION EV71vac is safe, well-tolerated, and highly effective in preventing EV71 associated diseases in children aged 2-71 months. FUNDING Medigen Vaccine Biologics and A+ Industrial Innovative R&D Program of the Ministry of Economic Affairs, Taiwan.
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Affiliation(s)
| | - Cheng-Hsun Chiu
- Department of Paediatrics, Chang Gung Children's Hospital, Chang Gung University College of Medicine, Taoyuan City, Taiwan
| | - Chien-Yu Lin
- Department of Paediatrics, Hsinchu MacKay Memorial Hospital, Hsinchu City, Taiwan; Department of Medicine, MacKay Medical College, New Taipei City, Taiwan
| | - Nan-Chang Chiu
- Department of Paediatrics, MacKay Children's Hospital, Taipei City, Taiwan; Department of Medicine, MacKay Medical College, New Taipei City, Taiwan
| | - Po-Yen Chen
- Section of Infectious Disease, Department of Paediatrics, Taichung Veterans General Hospital, Taichung City, Taiwan
| | - Thi Tuong Vy Le
- Pasteur Institute in Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Dang Ngan Le
- Centre for Disease Control of Tien Giang Province, Vietnam
| | - An Han Duong
- Centre for Disease Control of Dong Thap Province, Vietnam
| | | | | | - Huu Khanh Truong
- Department of Paediatrics, Children's Hospital 1 in Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Trong Lan Phan
- Pasteur Institute in Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | | | - Shin-Ru Shih
- Research Centre for Emerging Viral Infections, College of Medicine, Chang Gung University, Taoyuan City, Taiwan; Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan City, Taiwan
| | - Chung-Guei Huang
- Research Centre for Emerging Viral Infections, College of Medicine, Chang Gung University, Taoyuan City, Taiwan; Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan City, Taiwan
| | - Yi-Jen Weng
- Medigen Vaccine Biologics, Taipei City, Taiwan
| | | | | | - Charles Chen
- College of Science and Technology, Temple University, Philadelphia, PA, USA
| | - I-Chen Tai
- Medigen Vaccine Biologics, Taipei City, Taiwan.
| | - Li-Min Huang
- Department of Paediatrics, National Taiwan University Children's Hospital, Taipei City, Taiwan.
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Nguyen VL, Duong DL, Lee SH, Avila J, Han G, Kim YM, Asensio MC, Jeong SY, Lee YH. Author Correction: Layer-controlled single-crystalline graphene film with stacking order via Cu-Si alloy formation. Nat Nanotechnol 2021; 16:114-116. [PMID: 33288950 DOI: 10.1038/s41565-020-00821-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Affiliation(s)
- Van Luan Nguyen
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea
- Inorganic Materials Laboratory, Samsung Advanced Institute of Technology, Samsung Electronics, Suwon, Korea
| | - Dinh Loc Duong
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea
- Department of Energy Science, Department of Physics, Sungkyunkwan University, Suwon, Korea
| | - Sang Hyub Lee
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea
- Department of Energy Science, Department of Physics, Sungkyunkwan University, Suwon, Korea
| | - José Avila
- Synchrotron SOLEIL, Université Paris-Saclay, L'Orme des Merisiers Saint-Aubin, Gif sur Yvette, France
| | - Gyeongtak Han
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea
| | - Young-Min Kim
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea
- Department of Energy Science, Department of Physics, Sungkyunkwan University, Suwon, Korea
| | - Maria C Asensio
- Materials Science Institute of Madrid (ICMM), Spanish Scientific Research Council (CSIC), Cantoblanco, Madrid, Spain.
- MATINÉE: CSIC Associated Unit (ICMM-ICMUV Valencia University), Cantoblanco, Madrid, Spain.
| | - Se-Young Jeong
- Department of Cogno-mechatronics Engineering, Department of Optics and Mechatronics Engineering, Pusan National University, Busan, Republic of Korea.
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea.
- Department of Energy Science, Department of Physics, Sungkyunkwan University, Suwon, Korea.
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Tran MD, Lee SG, Jeon S, Kim ST, Kim H, Nguyen VL, Adhikari S, Woo S, Park HC, Kim Y, Kim JH, Lee YH. Decelerated Hot Carrier Cooling in Graphene via Nondissipative Carrier Injection from MoS 2. ACS Nano 2020; 14:13905-13912. [PMID: 32813494 DOI: 10.1021/acsnano.0c06311] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
One key to improve the performance of advanced optoelectronic devices and energy harvesting in graphene is to understand the predominant carrier scattering via optical phonons. Nevertheless, low light absorbance in graphene yields a limited photoexcited carrier density, hampering the hot carrier effect, which is strongly correlated to the hot optical phonon bottleneck effect as the energy-loss channel. Here, by integrating graphene with monolayer MoS2 possessing stronger light absorbance, we demonstrate an efficient interfacial hot carrier transfer between graphene and MoS2 in their heterostructure with a prolonged relaxation time using broadband transient differential transmittance spectroscopy. We observe that the carrier relaxation time of graphene in the heterostructure is 4 times slower than that of bare graphene. This is explained by nondissipative interlayer transfer from MoS2 to graphene, which is attributed to the enhanced hot optical phonon bottleneck effect of graphene in the heterostructure by an increased photoexcited carrier population. A significant reduction of both amplitude and relaxation time in A- and B-excitons is another evidence of the interlayer transfer from MoS2 to graphene. The nondissipative interlayer charge transfer from MoS2 to graphene is confirmed by density functional calculations. This provides a different platform to further study the photoinduced hot carrier effect in graphene heterostructures for photothermoelectric detectors or hot carrier solar cells.
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Affiliation(s)
- Minh Dao Tran
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Sung-Gyu Lee
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Sunam Jeon
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Sung-Tae Kim
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Hyun Kim
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
| | - Van Luan Nguyen
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
| | - Subash Adhikari
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Sungjong Woo
- Center for Theoretical Physics of Complex System, Institute for Basic Science (IBS), Daejeon 34126, Republic of Korea
| | - Hee Chul Park
- Center for Theoretical Physics of Complex System, Institute for Basic Science (IBS), Daejeon 34126, Republic of Korea
| | - Youngkuk Kim
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Department of Physics, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Ji-Hee Kim
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Physics, Sungkyunkwan University, Suwon 16419, Republic of Korea
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5
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Nguyen VL, Duong DL, Lee SH, Avila J, Han G, Kim YM, Asensio MC, Jeong SY, Lee YH. Layer-controlled single-crystalline graphene film with stacking order via Cu-Si alloy formation. Nat Nanotechnol 2020; 15:861-867. [PMID: 32719494 DOI: 10.1038/s41565-020-0743-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 06/24/2020] [Indexed: 06/11/2023]
Abstract
Multilayer graphene and its stacking order provide both fundamentally intriguing properties and technological engineering applications. Several approaches to control the stacking order have been demonstrated, but a method of precisely controlling the number of layers with desired stacking sequences is still lacking. Here, we propose an approach for controlling the layer thickness and crystallographic stacking sequence of multilayer graphene films at the wafer scale via Cu-Si alloy formation using direct chemical vapour deposition. C atoms are introduced by tuning the ultra-low-limit CH4 concentration to form a SiC layer, reaching one to four graphene layers at the wafer scale after Si sublimation. The crystallographic structure of single-crystalline or uniformly oriented bilayer (AB), trilayer (ABA) and tetralayer (ABCA) graphene are determined via nano-angle-resolved photoemission spectroscopy, which agrees with theoretical calculations, Raman spectroscopy and transport measurements. The present study takes a step towards the layer-controlled growth of graphite and other two-dimensional materials.
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Affiliation(s)
- Van Luan Nguyen
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea
- Inorganic Materials Laboratory, Samsung Advanced Institute of Technology, Samsung Electronics, Suwon, Korea
| | - Dinh Loc Duong
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea
- Department of Energy Science, Department of Physics, Sungkyunkwan University, Suwon, Korea
| | - Sang Hyub Lee
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea
- Department of Energy Science, Department of Physics, Sungkyunkwan University, Suwon, Korea
| | - José Avila
- Synchrotron SOLEIL, Université Paris-Saclay, L'Orme des Merisiers Saint-Aubin, Gif sur Yvette, France
| | - Gyeongtak Han
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea
| | - Young-Min Kim
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea
- Department of Energy Science, Department of Physics, Sungkyunkwan University, Suwon, Korea
| | - Maria C Asensio
- Materials Science Institute of Madrid (ICMM), Spanish Scientific Research Council (CSIC), Cantoblanco, Madrid, Spain.
- MATINÉE: CSIC Associated Unit (ICMM-ICMUV Valencia University), Cantoblanco, Madrid, Spain.
| | - Se-Young Jeong
- Department of Cogno-mechatronics Engineering, Department of Optics and Mechatronics Engineering, Pusan National University, Busan, Republic of Korea.
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea.
- Department of Energy Science, Department of Physics, Sungkyunkwan University, Suwon, Korea.
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Abstract
The quantum confinement of charge carriers has been a promising approach to enhance the efficiency of thermoelectric devices, by lowering the dimension of materials and raising the boundary phonon scattering rate. The role of quantum confinement in thermoelectric efficiency has been investigated by using macroscopic device-scale measurements based on diffusive electron transport with the thermal de Broglie wavelength of the electrons. Here, we report a new class of thermoelectric operation originating from quasi-bound state electrons in low-dimensional materials. Coherent thermoelectric power from confined charges was observed at room temperature in graphene quantum dots with diameters of several nanometers. The graphene quantum dots, electrostatically defined as circular n-p-n junctions to isolate charges in the p-type graphene quantum dots, enabled thermoelectric microscopy at the atomic scale, revealing weakly localized and coherent thermoelectric power generation. The conceptual thermoelectric operation provides new insights, selectively enhancing coherent thermoelectric power via resonant states of charge carriers in low-dimensional materials.
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Affiliation(s)
- Mali Zhao
- Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Korea
| | - Dohyun Kim
- Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Korea
| | - Van Luan Nguyen
- IBS Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science , Sungkyunkwan University , Suwon 16419 , Korea
| | - Jinbao Jiang
- Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Korea
- IBS Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science , Sungkyunkwan University , Suwon 16419 , Korea
| | - Linfeng Sun
- Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Korea
| | - Young Hee Lee
- Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Korea
- IBS Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science , Sungkyunkwan University , Suwon 16419 , Korea
| | - Heejun Yang
- Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Korea
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7
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Chen C, Avila J, Arezki H, Nguyen VL, Shen J, Mucha-Kruczyński M, Yao F, Boutchich M, Chen Y, Lee YH, Asensio MC. Retraction Note: Large local lattice expansion in graphene adlayers grown on copper. Nat Mater 2018; 17:1048. [PMID: 30262907 DOI: 10.1038/s41563-018-0185-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The authors unanimously wish to retract this Article due to their concerns about the interpretation of the low-energy electron microscopy (LEEM) and diffraction (LEED) patterns reported in the manuscript. In this study, the authors used spatial and angle-resolved photoemission spectroscopy (ARPES) to characterize graphene monolayers grown on copper foils, and observed regions of graphene adlayers with enhanced graphene/Cu interaction, higher Dirac cone doping level, moiré mini Dirac cones and large lattice expansion. All these properties have been clearly verified and reproduced by photoemission spectroscopy as well as explained by density functional theory. LEEM and LEED characterization were also carried out to confirm the existence of a moiré superlattice and lattice expansion, and the results were included in the main manuscript and Supplementary Information. On further analysis of the LEEM/LEED data, it seems that while the existence of a moiré superlattice can be corroborated, the conclusion of graphene lattice expansion (7%) based on spatially resolved ARPES determinations cannot be confirmed by the LEEM/LEED measurements. The authors realized that these measurements were collected from statistically non-representative areas of the sample. Moreover, the fact that the raw microLEED images bear an asymmetry factor of as much as 5% due to the instrumental aberration makes it impossible to estimate any compression or expansion of the same order. Consequently, their conclusion on the graphene lattice expansion can only be supported by the photoemission data. In view that more complete and reliable structural determinations should be conducted, all authors wish to retract this Article.
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Affiliation(s)
- Chaoyu Chen
- ANTARES Beamline, Synchrotron SOLEIL & Universite Paris-Saclay, L'Orme des Merisiers, Gif sur Yvette CEDEX, France
| | - José Avila
- ANTARES Beamline, Synchrotron SOLEIL & Universite Paris-Saclay, L'Orme des Merisiers, Gif sur Yvette CEDEX, France
| | - Hakim Arezki
- Group of Electrical Engineering-Paris, UMR CNRS 8507, CentraleSupelec, Univ. Paris-Sud, Universite Paris-Saclay; Sorbonne Universites, UPMC Univ Paris 06, Gif-sur-Yvette CEDEX, France
| | - Van Luan Nguyen
- IBS Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science, Sungkyunkwan University, Suwon, Korea
| | - Jiahong Shen
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong SAR, China
- Department of Materials Science, Fudan University, Shanghai, China
| | - Marcin Mucha-Kruczyński
- Department of Physics, University of Bath, Bath, UK
- Centre for Nanoscience and Nanotechnology, University of Bath, Bath, UK
| | - Fei Yao
- IBS Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science, Sungkyunkwan University, Suwon, Korea
| | - Mohamed Boutchich
- Group of Electrical Engineering-Paris, UMR CNRS 8507, CentraleSupelec, Univ. Paris-Sud, Universite Paris-Saclay; Sorbonne Universites, UPMC Univ Paris 06, Gif-sur-Yvette CEDEX, France.
| | - Yue Chen
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong SAR, China.
| | - Young Hee Lee
- IBS Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science, Sungkyunkwan University, Suwon, Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, Korea
| | - Maria C Asensio
- ANTARES Beamline, Synchrotron SOLEIL & Universite Paris-Saclay, L'Orme des Merisiers, Gif sur Yvette CEDEX, France.
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8
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Chen C, Avila J, Arezki H, Nguyen VL, Shen J, Mucha-Kruczyński M, Yao F, Boutchich M, Chen Y, Lee YH, Asensio MC. Large local lattice expansion in graphene adlayers grown on copper. Nat Mater 2018; 17:450-455. [PMID: 29632409 DOI: 10.1038/s41563-018-0053-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 03/06/2018] [Indexed: 06/08/2023]
Abstract
Variations of the lattice parameter can significantly change the properties of a material, and, in particular, its electronic behaviour. In the case of graphene, however, variations of the lattice constant with respect to graphite have been limited to less than 2.5% due to its well-established high in-plane stiffness. Here, through systematic electronic and lattice structure studies, we report regions where the lattice constant of graphene monolayers grown on copper by chemical vapour deposition increases up to ~7.5% of its relaxed value. Density functional theory calculations confirm that this expanded phase is energetically metastable and driven by the enhanced interaction between the substrate and the graphene adlayer. We also prove that this phase possesses distinctive chemical and electronic properties. The inherent phase complexity of graphene grown on copper foils revealed in this study may inspire the investigation of possible metastable phases in other seemingly simple heterostructure systems.
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Affiliation(s)
- Chaoyu Chen
- ANTARES Beamline, Synchrotron SOLEIL & Université Paris-Saclay, L'Orme des Merisiers, Gif sur Yvette CEDEX, France
| | - José Avila
- ANTARES Beamline, Synchrotron SOLEIL & Université Paris-Saclay, L'Orme des Merisiers, Gif sur Yvette CEDEX, France
| | - Hakim Arezki
- Group of Electrical Engineering-Paris, UMR CNRS 8507, CentraleSupélec, Univ. Paris-Sud, Université Paris-Saclay; Sorbonne Universités, UPMC Univ Paris 06, Gif-sur-Yvette CEDEX, France
| | - Van Luan Nguyen
- IBS Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science, Sungkyunkwan University, Suwon, Korea
| | - Jiahong Shen
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong SAR, China
- Department of Materials Science, Fudan University, Shanghai, China
| | - Marcin Mucha-Kruczyński
- Department of Physics, University of Bath, Bath, UK
- Centre for Nanoscience and Nanotechnology, University of Bath, Bath, UK
| | - Fei Yao
- IBS Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science, Sungkyunkwan University, Suwon, Korea
| | - Mohamed Boutchich
- Group of Electrical Engineering-Paris, UMR CNRS 8507, CentraleSupélec, Univ. Paris-Sud, Université Paris-Saclay; Sorbonne Universités, UPMC Univ Paris 06, Gif-sur-Yvette CEDEX, France.
| | - Yue Chen
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong SAR, China.
| | - Young Hee Lee
- IBS Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science, Sungkyunkwan University, Suwon, Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, Korea
| | - Maria C Asensio
- ANTARES Beamline, Synchrotron SOLEIL & Université Paris-Saclay, L'Orme des Merisiers, Gif sur Yvette CEDEX, France.
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9
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Kar S, Nguyen VL, Mohapatra DR, Lee YH, Sood AK. Ultrafast Spectral Photoresponse of Bilayer Graphene: Optical Pump-Terahertz Probe Spectroscopy. ACS Nano 2018; 12:1785-1792. [PMID: 29309138 DOI: 10.1021/acsnano.7b08555] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Photoinduced terahertz conductivity Δσ(ω) of Bernal stacked bilayer graphene (BLG) with different dopings is measured by time-resolved optical pump terahertz probe spectroscopy. The real part of photoconductivity Δσ(ω) (ΔσRe(ω)) is positive throughout the spectral range 0.5-2.5 THz in low-doped BLG. This is in sharp contrast to Δσ(ω) for high-doped bilayer graphene where ΔσRe(ω) is negative at low frequency and positive on the high frequency side. We use Boltzmann transport theory to understand quantitatively the frequency dependence of Δσ(ω), demanding the energy dependence of different scattering rates such as short-range impurity scattering, Coulomb scattering, carrier-acoustic phonon scattering, and substrate surface optical phonon scattering. We find that the short-range disorder scattering dominates over other processes. The calculated photoconductivity captures very well the experimental conductivity spectra as a function of lattice temperature varying from 300 to 4 K, without any empirical fitting procedures adopted so far in the literature. This helps us to understand the intraband conductivity of photoexcited hot carriers in 2D materials.
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Affiliation(s)
- Srabani Kar
- Department of Physics, Indian Institute of Science , Bangalore 560 012, India
- Center for Ultrafast Laser Applications, Indian Institute of Science , Bangalore 560 012, India
| | - Van Luan Nguyen
- Center for Intergrated Nanostructure Physics (CINAP), Institute for Basic Science, Sungkyunkwan University , Suwon 16419, Korea
| | - Dipti R Mohapatra
- Department of Physics, Indian Institute of Science , Bangalore 560 012, India
| | - Young Hee Lee
- Center for Intergrated Nanostructure Physics (CINAP), Institute for Basic Science, Sungkyunkwan University , Suwon 16419, Korea
- Department of Energy Science and Department of Physics, Sungkyunkwan University , Suwon 16419, Korea
| | - A K Sood
- Department of Physics, Indian Institute of Science , Bangalore 560 012, India
- Center for Ultrafast Laser Applications, Indian Institute of Science , Bangalore 560 012, India
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10
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Shin HJ, Kim J, Kim S, Kim H, Nguyen VL, Lee YH, Lim SC, Son JH. Transient Carrier Cooling Enhanced by Grain Boundaries in Graphene Monolayer. ACS Appl Mater Interfaces 2017; 9:41026-41033. [PMID: 29072440 DOI: 10.1021/acsami.7b12812] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Using a high terahertz (THz) electric field (ETHz), the carrier scattering in graphene was studied with an electric field of up to 282 kV/cm. When the grain size of graphene monolayers varies from small (5 μm) and medium (70 μm) to large grains (500 μm), the dominant carrier scattering source in large- and small-grained graphene differs at high THz field, i.e., there is optical phonon scattering for large grains and defect scattering for small grains. Although the electron-optical phonon coupling strength is the same for all grain sizes in our study, the enhanced optical phonon scattering in the high THz field from the large-grained graphene is caused by a higher optical phonon temperature, originating from the slow relaxation of accelerated electrons. Unlike the large-grained graphene, lower electron and optical phonon temperatures are found in the small-grained graphene monolayer, resulting from the effective carrier cooling through the defects, called supercollisions. Our results indicate that the carrier mobility in the high-crystalline graphene is easily vulnerable to scattering by the optical phonons. Thus, controlling the population of defect sites, as a means for carrier cooling, can enhance the carrier mobility at high electric fields in graphene electronics by suppressing the heating of optical phonons.
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Affiliation(s)
- Hee Jun Shin
- Department of Physics, University of Seoul , Seoul 02504, Republic of Korea
- Research Group of Food Safety, Korea Food Research Institute , Wanju 55365, Republic of Korea
| | | | | | - Hyeongmun Kim
- Department of Physics, University of Seoul , Seoul 02504, Republic of Korea
| | | | | | | | - Joo-Hiuk Son
- Department of Physics, University of Seoul , Seoul 02504, Republic of Korea
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11
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Vu QA, Kim H, Nguyen VL, Won UY, Adhikari S, Kim K, Lee YH, Yu WJ. A High-On/Off-Ratio Floating-Gate Memristor Array on a Flexible Substrate via CVD-Grown Large-Area 2D Layer Stacking. Adv Mater 2017; 29. [PMID: 28949418 DOI: 10.1002/adma.201703363] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 08/04/2017] [Indexed: 05/09/2023]
Abstract
Memristors such as phase-change memory and resistive memory have been proposed to emulate the synaptic activities in neuromorphic systems. However, the low reliability of these types of memories is their biggest challenge for commercialization. Here, a highly reliable memristor array using floating-gate memory operated by two terminals (source and drain) using van der Waals layered materials is demonstrated. Centimeter-scale samples (1.5 cm × 1.5 cm) of MoS2 as a channel and graphene as a trap layer grown by chemical vapor deposition (CVD) are used for array fabrication with Al2 O3 as the tunneling barrier. With regard to the memory characteristics, 93% of the devices exhibit an on/off ratio of over 103 with an average ratio of 104 . The high on/off ratio and reliable endurance in the devices allow stable 6-level memory applications. The devices also exhibit excellent memory durability over 8000 cycles with a negligible shift in the threshold voltage and on-current, which is a significant improvement over other types of memristors. In addition, the devices can be strained up to 1% by fabricating on a flexible substrate. This demonstration opens a practical route for next-generation electronics with CVD-grown van der Waals layered materials.
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Affiliation(s)
- Quoc An Vu
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Hyun Kim
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Van Luan Nguyen
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, 16419, Republic of Korea
| | - Ui Yeon Won
- Department of Electronic and Electrical Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Subash Adhikari
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Kunnyun Kim
- Korea Electronics Technology Institute, Seongnam, 13509, Republic of Korea
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Woo Jong Yu
- Department of Electronic and Electrical Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea
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12
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Vu QA, Lee JH, Nguyen VL, Shin YS, Lim SC, Lee K, Heo J, Park S, Kim K, Lee YH, Yu WJ. Tuning Carrier Tunneling in van der Waals Heterostructures for Ultrahigh Detectivity. Nano Lett 2017; 17:453-459. [PMID: 27983857 DOI: 10.1021/acs.nanolett.6b04449] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Semiconducting transition metal dichalcogenides (TMDs) are promising materials for photodetection over a wide range of visible wavelengths. Photodetection is generally realized via a phototransistor, photoconductor, p-n junction photovoltaic device, and thermoelectric device. The photodetectivity, which is a primary parameter in photodetector design, is often limited by either low photoresponsivity or a high dark current in TMDs materials. Here, we demonstrated a highly sensitive photodetector with a MoS2/h-BN/graphene heterostructure, by inserting a h-BN insulating layer between graphene electrode and MoS2 photoabsorber, the dark-carriers were highly suppressed by the large electron barrier (2.7 eV) at the graphene/h-BN junction while the photocarriers were effectively tunneled through small hole barrier (1.2 eV) at the MoS2/h-BN junction. With both high photocurrent/dark current ratio (>105) and high photoresponsivity (180 AW-1), ultrahigh photodetectivity of 2.6 × 1013 Jones was obtained at 7 nm thick h-BN, about 100-1000 times higher than that of previously reported MoS2-based devices.
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Affiliation(s)
- Quoc An Vu
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Korea
| | - Jin Hee Lee
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Korea
| | - Van Luan Nguyen
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Korea
| | | | - Seong Chu Lim
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Korea
| | - Kiyoung Lee
- Samsung Advanced Institute of Technology , Suwon, 16678, Korea
| | - Jinseong Heo
- Samsung Advanced Institute of Technology , Suwon, 16678, Korea
| | - Seongjun Park
- Samsung Advanced Institute of Technology , Suwon, 16678, Korea
| | - Kunnyun Kim
- Korea Electronics Technology Institute , Seongnam, 13509, Republic of Korea
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Korea
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13
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Ta HQ, Perello DJ, Duong DL, Han GH, Gorantla S, Nguyen VL, Bachmatiuk A, Rotkin SV, Lee YH, Rümmeli MH. Stranski-Krastanov and Volmer-Weber CVD Growth Regimes To Control the Stacking Order in Bilayer Graphene. Nano Lett 2016; 16:6403-6410. [PMID: 27683947 DOI: 10.1021/acs.nanolett.6b02826] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Aside from unusual properties of monolayer graphene, bilayer has been shown to have even more interesting physics, in particular allowing bandgap opening with dual gating for proper interlayer symmetry. Such properties, promising for device applications, ignited significant interest in understanding and controlling the growth of bilayer graphene. Here we systematically investigate a broad set of flow rates and relative gas ratio of CH4 to H2 in atmospheric pressure chemical vapor deposition of multilayered graphene. Two very different growth windows are identified. For relatively high CH4 to H2 ratios, graphene growth is relatively rapid with an initial first full layer forming in seconds upon which new graphene flakes nucleate then grow on top of the first layer. The stacking of these flakes versus the initial graphene layer is mostly turbostratic. This growth mode can be likened to Stranski-Krastanov growth. With relatively low CH4 to H2 ratios, growth rates are reduced due to a lower carbon supply rate. In addition bi-, tri-, and few-layer flakes form directly over the Cu substrate as individual islands. Etching studies show that in this growth mode subsequent layers form beneath the first layer presumably through carbon radical intercalation. This growth mode is similar to that found with Volmer-Weber growth and was shown to produce highly oriented AB-stacked materials. These systematic studies provide new insight into bilayer graphene formation and define the synthetic range where gapped bilayer graphene can be reliably produced.
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Affiliation(s)
- Huy Q Ta
- College of Physics, Optoelectronics and Energy & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University , Suzhou 215006, China
- Centre of Polymer and Carbon Materials, Polish Academy of Sciences , M. Curie-Sklodowskiej 34, Zabrze 41-819, Poland
- Department of Energy Science, Department of Physics, Sungkyunkwan University , Suwon 16419, Republic of Korea
| | - David J Perello
- Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University , Suwon 16419, Republic of Korea
| | - Dinh Loc Duong
- Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University , Suwon 16419, Republic of Korea
| | - Gang Hee Han
- Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University , Suwon 16419, Republic of Korea
| | - Sandeep Gorantla
- Department of Physics, University of Oslo , Blindern, P.O. Box 1048, 0316 Oslo, Norway
| | - Van Luan Nguyen
- Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University , Suwon 16419, Republic of Korea
| | - Alicja Bachmatiuk
- Centre of Polymer and Carbon Materials, Polish Academy of Sciences , M. Curie-Sklodowskiej 34, Zabrze 41-819, Poland
- IFW Dresden, P.O. Box 270116, D-01171 Dresden, Germany
| | - Slava V Rotkin
- Department of Physics and Center for Advanced Materials and Nanotechnology, Lehigh University , Bethlehem, Pennsylvania 18015, United States
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University , Suwon 16419, Republic of Korea
- Department of Energy Science, Department of Physics, Sungkyunkwan University , Suwon 16419, Republic of Korea
| | - Mark H Rümmeli
- College of Physics, Optoelectronics and Energy & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University , Suzhou 215006, China
- Centre of Polymer and Carbon Materials, Polish Academy of Sciences , M. Curie-Sklodowskiej 34, Zabrze 41-819, Poland
- IFW Dresden, P.O. Box 270116, D-01171 Dresden, Germany
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14
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Nguyen VL, Perello DJ, Lee S, Nai CT, Shin BG, Kim JG, Park HY, Jeong HY, Zhao J, Vu QA, Lee SH, Loh KP, Jeong SY, Lee YH. Wafer-Scale Single-Crystalline AB-Stacked Bilayer Graphene. Adv Mater 2016; 28:8177-8183. [PMID: 27414480 DOI: 10.1002/adma.201601760] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 06/19/2016] [Indexed: 06/06/2023]
Abstract
Single-crystalline artificial AB-stacked bilayer graphene is formed by aligned transfer of two single-crystalline monolayers on a wafer-scale. The obtained bilayer has a well-defined interface and is electronically equivalent to exfoliated or direct-grown AB-stacked bilayers.
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Affiliation(s)
- Van Luan Nguyen
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Physics, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - David J Perello
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Seunghun Lee
- Department of Cogno-mechatronics Engineering, Pusan National University, Busan, 46241, Republic of Korea
| | - Chang Tai Nai
- Department of Chemistry and Centre for Advanced 2D Materials (CA2DM), National University of Singapore, 3 Science Drive 3, Singapore, 117543
| | - Bong Gyu Shin
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Joong-Gyu Kim
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Physics, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Ho Yeol Park
- Department of Cogno-mechatronics Engineering, Pusan National University, Busan, 46241, Republic of Korea
| | - Hu Young Jeong
- UNIST Central Research Facilities, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 689-798, Republic of Korea
| | - Jiong Zhao
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Quoc An Vu
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Physics, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Sang Hyub Lee
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Physics, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Kian Ping Loh
- Department of Chemistry and Centre for Advanced 2D Materials (CA2DM), National University of Singapore, 3 Science Drive 3, Singapore, 117543
| | - Se-Young Jeong
- Department of Cogno-mechatronics Engineering, Pusan National University, Busan, 46241, Republic of Korea.
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Republic of Korea.
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
- Department of Physics, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
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15
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Joo MK, Kim J, Park JH, Nguyen VL, Kim KK, Lee YH, Suh D. Large-Scale Graphene on Hexagonal-BN Hall Elements: Prediction of Sensor Performance without Magnetic Field. ACS Nano 2016; 10:8803-8811. [PMID: 27580305 DOI: 10.1021/acsnano.6b04547] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A graphene Hall element (GHE) is an optimal system for a magnetic sensor because of its perfect two-dimensional (2-D) structure, high carrier mobility, and widely tunable carrier concentration. Even though several proof-of-concept devices have been proposed, manufacturing them by mechanical exfoliation of 2-D material or electron-beam lithography is of limited feasibility. Here, we demonstrate a high quality GHE array having a graphene on hexagonal-BN (h-BN) heterostructure, fabricated by photolithography and large-area 2-D materials grown by chemical vapor deposition techniques. A superior performance of GHE was achieved with the help of a bottom h-BN layer, and showed a maximum current-normalized sensitivity of 1986 V/AT, a minimum magnetic resolution of 0.5 mG/Hz(0.5) at f = 300 Hz, and an effective dynamic range larger than 74 dB. Furthermore, on the basis of a thorough understanding of the shift of charge neutrality point depending on various parameters, an analytical model that predicts the magnetic sensor operation of a GHE from its transconductance data without magnetic field is proposed, simplifying the evaluation of each GHE design. These results demonstrate the feasibility of this highly performing graphene device using large-scale manufacturing-friendly fabrication methods.
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Affiliation(s)
- Min-Kyu Joo
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea
| | - Joonggyu Kim
- Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea
| | - Ji-Hoon Park
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
| | - Van Luan Nguyen
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
| | - Ki Kang Kim
- Department of Energy and Materials Engineering, Dongguk University , Seoul 04620, Republic of Korea
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea
| | - Dongseok Suh
- Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea
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16
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Vu QA, Shin YS, Kim YR, Nguyen VL, Kang WT, Kim H, Luong DH, Lee IM, Lee K, Ko DS, Heo J, Park S, Lee YH, Yu WJ. Two-terminal floating-gate memory with van der Waals heterostructures for ultrahigh on/off ratio. Nat Commun 2016; 7:12725. [PMID: 27586841 PMCID: PMC5025799 DOI: 10.1038/ncomms12725] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 07/27/2016] [Indexed: 12/18/2022] Open
Abstract
Concepts of non-volatile memory to replace conventional flash memory have suffered from low material reliability and high off-state current, and the use of a thick, rigid blocking oxide layer in flash memory further restricts vertical scale-up. Here, we report a two-terminal floating gate memory, tunnelling random access memory fabricated by a monolayer MoS2/h-BN/monolayer graphene vertical stack. Our device uses a two-terminal electrode for current flow in the MoS2 channel and simultaneously for charging and discharging the graphene floating gate through the h-BN tunnelling barrier. By effective charge tunnelling through crystalline h-BN layer and storing charges in graphene layer, our memory device demonstrates an ultimately low off-state current of 10(-14) A, leading to ultrahigh on/off ratio over 10(9), about ∼10(3) times higher than other two-terminal memories. Furthermore, the absence of thick, rigid blocking oxides enables high stretchability (>19%) which is useful for soft electronics.
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Affiliation(s)
- Quoc An Vu
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea.,Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Yong Seon Shin
- Department of Electronic and Electrical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Young Rae Kim
- Department of Electronic and Electrical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Van Luan Nguyen
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea.,Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Won Tae Kang
- Department of Electronic and Electrical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Hyun Kim
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea.,Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Dinh Hoa Luong
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea.,Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Il Min Lee
- Department of Electronic and Electrical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Kiyoung Lee
- Samsung Advanced Institute of Technology, Suwon 16678, Republic of Korea
| | - Dong-Su Ko
- Samsung Advanced Institute of Technology, Suwon 16678, Republic of Korea
| | - Jinseong Heo
- Samsung Advanced Institute of Technology, Suwon 16678, Republic of Korea
| | - Seongjun Park
- Samsung Advanced Institute of Technology, Suwon 16678, Republic of Korea
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea.,Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Woo Jong Yu
- Department of Electronic and Electrical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea.,Samsung-SKKU Graphene Center (SSGC), Sungkyunkwan University, Suwon 16419, Republic of Korea
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17
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Nguyen VH, Nguyen VL, Hoang NS, Do TK. Effect of cell membrane permeability protein on porcine oocyte vitrification. Cryo Letters 2016; 37:103-109. [PMID: 27224521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
BACKGROUND The discovery of proteins with inherent cell membrane-translocating activity will expand our ability to study and manipulate various intracellular processes in living systems. OBJECTIVE We investigated the effect of TAT-EGFP (trans-activator of transcription-enhanced green fluorescent protein) intra-cellular delivery on the survival and development of mature porcine oocytes after cryopreservasion. MATERIALS AND METHODS Cumulus-oocyte complexes (COCs) collected from follicles 3 to 6 mm in diameter in abattoir-derived oocytesries of prepubertal gilts were on vitro matured (IVM). After IVM, the oocytes were used for TAT-EGFP delivery test and cryopreservation with and without TAT-EGFP supplementation. Oocyte viability was assayed by staining with fluorescein diacetate. Live oocytes were parthened and cultured in vitro, to assess their ability to be activated and to therefore develop. RESULTS The results show that the TAT-EGFP was well delivered into the nuclear of the Hela cell and oocytes also. In the medium toxic test, the proportion of viable oocytes in seven groups showed no significance. In vitrification experiments, the viability of oocytes in group supplemented with TAT-EGFP was significantly higher than that in the without TAT-EGFP group and the control groups (27.7%, 90.4%, and 100%, respectively). Among the three groups, the developmental abilities of oocytes in the supplement TAT-EGFP, EGFP and Control groups revealed that the vitrified group had a significantly reduced ability to undergo first cleavage (34.4%, 63.3%, and 69.0%, respectively). CONCLUSION the supplement of TAT-EGFP protein into vitrification medium does not affect the viability of the oocytes whereas it improved the viability and developmental potential of oocytes after it was vitrified.
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Affiliation(s)
- V H Nguyen
- Laboratory of Embryo Biotechnology, Institute of Biotechnology, Vietnam Academy of Science and Technology, Hanoi, Vietnam.
| | - V L Nguyen
- Laboratory of Embryo Biotechnology, Institute of Biotechnology, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - N S Hoang
- Department of Animal Biotechnology, Institute of Tropical Biology, Vietnam Academy of Science and Technology, Ho Chi Minh City, Vietnam
| | - T K Do
- Fisheries College, Tuson District, Bacninh Province, Vietnam
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18
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Bazylewski PF, Nguyen VL, Bauer RPC, Hunt AH, McDermott EJG, Leedahl BD, Kukharenko AI, Cholakh SO, Kurmaev EZ, Blaha P, Moewes A, Lee YH, Chang GS. Selective Area Band Engineering of Graphene using Cobalt-Mediated Oxidation. Sci Rep 2015; 5:15380. [PMID: 26486966 PMCID: PMC4614253 DOI: 10.1038/srep15380] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 09/23/2015] [Indexed: 11/09/2022] Open
Abstract
This study reports a scalable and economical method to open a band gap in single layer graphene by deposition of cobalt metal on its surface using physical vapor deposition in high vacuum. At low cobalt thickness, clusters form at impurity sites on the graphene without etching or damaging the graphene. When exposed to oxygen at room temperature, oxygen functional groups form in proportion to the cobalt thickness that modify the graphene band structure. Cobalt/Graphene resulting from this treatment can support a band gap of 0.30 eV, while remaining largely undamaged to preserve its structural and electrical properties. A mechanism of cobalt-mediated band opening is proposed as a two-step process starting with charge transfer from metal to graphene, followed by formation of oxides where cobalt has been deposited. Contributions from the formation of both CoO and oxygen functional groups on graphene affect the electronic structure to open a band gap. This study demonstrates that cobalt-mediated oxidation is a viable method to introduce a band gap into graphene at room temperature that could be applicable in electronics applications.
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Affiliation(s)
- Paul F Bazylewski
- Department of Physics and Engineering Physics, University of Saskatchewan, 116 Science Place, Saskatoon, SK, S7N 5E2, Canada
| | - Van Luan Nguyen
- Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University, Suwon 440-746, Korea
| | - Robert P C Bauer
- Department of Physics and Engineering Physics, University of Saskatchewan, 116 Science Place, Saskatoon, SK, S7N 5E2, Canada
| | - Adrian H Hunt
- Department of Physics and Engineering Physics, University of Saskatchewan, 116 Science Place, Saskatoon, SK, S7N 5E2, Canada
| | - Eamon J G McDermott
- Institute Materials Chemistry, Vienna University of Technology, Getreidemarkt 9/165-TC, A-1060 Vienna, Austria
| | - Brett D Leedahl
- Department of Physics and Engineering Physics, University of Saskatchewan, 116 Science Place, Saskatoon, SK, S7N 5E2, Canada
| | - Andrey I Kukharenko
- Institute of Metal Physics, Russian Academy of Sciences-Ural Division, 620990 Yekaterinburg, Russia.,Ural Federal University, 19 Mira Str., 620002 Yekaterinburg, Russia
| | - Seif O Cholakh
- Ural Federal University, 19 Mira Str., 620002 Yekaterinburg, Russia
| | - Ernst Z Kurmaev
- Institute of Metal Physics, Russian Academy of Sciences-Ural Division, 620990 Yekaterinburg, Russia.,Ural Federal University, 19 Mira Str., 620002 Yekaterinburg, Russia
| | - Peter Blaha
- Institute Materials Chemistry, Vienna University of Technology, Getreidemarkt 9/165-TC, A-1060 Vienna, Austria
| | - Alexander Moewes
- Department of Physics and Engineering Physics, University of Saskatchewan, 116 Science Place, Saskatoon, SK, S7N 5E2, Canada
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University, Suwon 440-746, Korea.,Department of Physics and Department of Energy Science, Sungkyunkwan University, Suwon 440-746, Korea
| | - Gap Soo Chang
- Department of Physics and Engineering Physics, University of Saskatchewan, 116 Science Place, Saskatoon, SK, S7N 5E2, Canada
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19
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Nguyen VL, Lee YH. Towards Wafer-Scale Monocrystalline Graphene Growth and Characterization. Small 2015; 11:3512-28. [PMID: 25903119 DOI: 10.1002/smll.201500147] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Revised: 03/02/2015] [Indexed: 05/08/2023]
Abstract
Since its discovery in 2004, graphene has boosted numerous fundamental sciences and technological applications due to its massless Dirac particle-like linear band dispersion, that causes unprecedented physical properties. Among the various methods for synthesizing graphene, chemical vapor deposition is the most suitable approach for scalable production on a wafer scale, which is a critical step for practical applications. Graphene grain boundaries (GGBs), consisting of nonhexagonal carbon rings and therefore modulating the properties of graphene films, are inevitably formed via the merging of adjacent graphene domains with different orientations. Large-area monocrystalline graphene synthesis without forming GGBs has been challenging, let alone observing such boundaries. Here, an up-to-date review is presented of how to grow wafer-scale monocrystalline graphene without GGBs. One approach is to make single domain sizes as large as possible by reducing or passivating the number of nucleation sites. Another approach is to align graphene domains in identical orientations, and then merge them atomically. The recently developed methods for observing graphene orientation and GGBs both at the atomic and macro-scales are also presented. Finally, perspectives for future research in graphene growth are discussed.
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Affiliation(s)
- Van Luan Nguyen
- IBS Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 440-746, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, 440-746, Republic of Korea
| | - Young Hee Lee
- IBS Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 440-746, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, 440-746, Republic of Korea
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20
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Lim YJ, Lee BH, Kwon YR, Choi YE, Murali G, Lee JH, Nguyen VL, Lee YH, Lee SH. Monitoring defects on monolayer graphene using nematic liquid crystals. Opt Express 2015; 23:14162-14167. [PMID: 26072784 DOI: 10.1364/oe.23.014162] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Defects in graphene governs electrical and optical properties. Although grain boundaries in graphene inevitably formed during large area synthesis process, which act as scattering centers for charge carriers to degrade mobility, have been studied extensively, point defects have been rarely investigated mainly due to the absence of facile observation tools. Here, we report polarized optical microscopy to observe defect distributions in monolayer graphene. This was realized by aligning liquid crystal s (LC) on graphene where the defect population was modulated by irradiating ultraviolet (UV) light directly on graphene surface under moisture condition. Aromatic rings in LC molecules are oriented with hexagonal rings in graphene to have preferred orientation, providing a way to identify relative orientations of graphene domains and point defects. Our studies show that point defects generated by prolonged UV irradiation time give rise to irregular LC alignment with disclination lines on the graphene surface and a large-size LC domain associated with graphene single domain eventually disappeared. This indicates that defects associated with oxygen-containing functional groups cause to reduce the strong stacking interaction between graphene and LC molecules.
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21
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Nguyen VL, Shin BG, Duong DL, Kim ST, Perello D, Lim YJ, Yuan QH, Ding F, Jeong HY, Shin HS, Lee SM, Chae SH, Vu QA, Lee SH, Lee YH. Seamless stitching of graphene domains on polished copper (111) foil. Adv Mater 2015; 27:1376-82. [PMID: 25523458 DOI: 10.1002/adma.201404541] [Citation(s) in RCA: 146] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 11/13/2014] [Indexed: 05/23/2023]
Abstract
Seamless stitching of graphene domains on polished copper (111) is proved clearly not only at atomic scale by scanning tunnelling microscopy (STM) and transmission electron micoscopy (TEM), but also at the macroscale by optical microscopy after UV-treatment. Using this concept of seamless stitching, synthesis of 6 cm × 3 cm monocrystalline graphene without grain boundaries on polished copper (111) foil is possible, which is only limited by the chamber size.
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Affiliation(s)
- Van Luan Nguyen
- IBS Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 440-746, Republic of Korea; Department of Energy Science, Department of Physics, Sungkyunkwan University, Suwon, 440-746, Republic of Korea
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22
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Cummings AW, Duong DL, Nguyen VL, Van Tuan D, Kotakoski J, Barrios Vargas JE, Lee YH, Roche S. Charge transport in polycrystalline graphene: challenges and opportunities. Adv Mater 2014; 26:5079-94. [PMID: 24903153 DOI: 10.1002/adma.201401389] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 04/30/2014] [Indexed: 05/27/2023]
Abstract
Graphene has attracted significant interest both for exploring fundamental science and for a wide range of technological applications. Chemical vapor deposition (CVD) is currently the only working approach to grow graphene at wafer scale, which is required for industrial applications. Unfortunately, CVD graphene is intrinsically polycrystalline, with pristine graphene grains stitched together by disordered grain boundaries, which can be either a blessing or a curse. On the one hand, grain boundaries are expected to degrade the electrical and mechanical properties of polycrystalline graphene, rendering the material undesirable for many applications. On the other hand, they exhibit an increased chemical reactivity, suggesting their potential application to sensing or as templates for synthesis of one-dimensional materials. Therefore, it is important to gain a deeper understanding of the structure and properties of graphene grain boundaries. Here, we review experimental progress on identification and electrical and chemical characterization of graphene grain boundaries. We use numerical simulations and transport measurements to demonstrate that electrical properties and chemical modification of graphene grain boundaries are strongly correlated. This not only provides guidelines for the improvement of graphene devices, but also opens a new research area of engineering graphene grain boundaries for highly sensitive electro-biochemical devices.
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Affiliation(s)
- Aron W Cummings
- ICN2 - Institut Català de Nanociència i Nanotecnologia, Campus UAB, 08193, Bellaterra, Barcelona, Spain
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23
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Metwally S, Mohamed F, Faaberg K, Burrage T, Prarat M, Moran K, Bracht A, Mayr G, Berninger M, Koster L, To TL, Nguyen VL, Reising M, Landgraf J, Cox L, Lubroth J, Carrillo C. Pathogenicity and molecular characterization of emerging porcine reproductive and respiratory syndrome virus in Vietnam in 2007. Transbound Emerg Dis 2010; 57:315-29. [PMID: 20629970 DOI: 10.1111/j.1865-1682.2010.01152.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In 2007, Vietnam experienced swine disease outbreaks causing clinical signs similar to the 'porcine high fever disease' that occurred in China during 2006. Analysis of diagnostic samples from the disease outbreaks in Vietnam identified porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV-2). Additionally, Escherichia coli and Streptococcus equi subspecies zooepidemicus were cultured from lung and spleen, and Streptococcus suis from one spleen sample. Genetic characterization of the Vietnamese PRRSV isolates revealed that this virus belongs to the North American genotype (type 2) with a high nucleotide identity to the recently reported Chinese strains. Amino acid sequence in the nsp2 region revealed 95.7-99.4% identity to Chinese strain HUN4, 68-69% identity to strain VR-2332 and 58-59% identity to strain MN184. A partial deletion in the nsp2 gene was detected; however, this deletion did not appear to enhance the virus pathogenicity in the inoculated pigs. Animal inoculation studies were conducted to determine the pathogenicity of PRRSV and to identify other possible agents present in the original specimens. Pigs inoculated with PRRSV alone and their contacts showed persistent fever, and two of five pigs developed cough, neurological signs and swollen joints. Necropsy examination showed mild to moderate bronchopneumonia, enlarged lymph nodes, fibrinous pericarditis and polyarthritis. PRRSV was re-isolated from blood and tissues of the inoculated and contact pigs. Pigs inoculated with lung and spleen tissue homogenates from sick pigs from Vietnam developed high fever, septicaemia, and died acutely within 72 h, while their contact pigs showed no clinical signs throughout the experiment. Streptococcus equi subspecies zooepidemicus was cultured, and PRRSV was re-isolated only from the inoculated pigs. Results suggest that the cause of the swine deaths in Vietnam is a multifactorial syndrome with PRRSV as a major factor.
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Affiliation(s)
- S Metwally
- FAO Reference Center for Vesicular Diseases, USDA, APHIS, Foreign Animal Disease Diagnostic Laboratory, National Veterinary Service Laboratories (NVSL), Plum Island Animal Disease Center (PIADC), Greenport, NY, USA.
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24
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Nguyen TT, Ménétrey F, Genini S, Nguyen VL, Vögeli P, Nguyen BX, Stranzinger G. Application of bovine microsatellite markers on Saola (Pseudoryx nghetinhensis). J Anim Breed Genet 2005; 122:195-8. [PMID: 16130471 DOI: 10.1111/j.1439-0388.2005.00511.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The aim of the present study was to assess the applicability of bovine microsatellite markers on Saola (Pseudoryx nghetinhensis). A total of 127 microsatellite markers were tested on a male and a young female Saola. An efficient amplification was observed for 123 markers (96.8%), 73 markers (59.3%) were polymorphic. Four loci (BM2304, BMS1928, BMS779 and ILSTS006) on cattle chromosomes 1, 4, 7 and 8, respectively, failed to amplify in Saola. Two cattle Y-chromosome-specific microsatellite markers (INRA126 and BM861) were successfully amplified from both sexes in Saola. However, two additional markers (INRA124 and INRA189) on Y-chromosome failed to amplify in the female animal. These results show that most of the bovine microsatellite markers are applicable in Saola and therefore they can be used to study the phylogenetic relationships and the genetic diversity of the Saola population.
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Affiliation(s)
- T T Nguyen
- Institute of Animal Sciences, Swiss Federal Institute of Technology, Zurich, Switzerland
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25
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Nguyen VL, Tonnelier M, Majer L, Dehouve A. [A rare cause of the Pierre Marie syndrome: cancer of the cavum (author's transl)]. Ann Radiol (Paris) 1979; 22:39-44. [PMID: 485058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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