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Haque A, Karmakar S, Trivedi RK, Chakraborty B, Droopad R. Electric-Field Emission Mechanism in Q-Carbon Field Emitters. ACS OMEGA 2023; 8:9307-9318. [PMID: 36936320 PMCID: PMC10018518 DOI: 10.1021/acsomega.2c07576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Accepted: 02/01/2023] [Indexed: 06/18/2023]
Abstract
In this paper, we report the excellent field emission properties of Q-carbon and analyze its field emission characteristics through structural, morphological, and electronic property correlations, supported by density functional theory (DFT) simulation studies. The Q-carbon field emitters show impressive and stable field emission properties, such as a low turn-on electric field of ∼2.38 V/μm, a high emission current density of ∼33 μA/cm2, and a critical field of ∼2.44 V/μm for the transition from a linear region to the saturation region in the F-N plot. The outstanding field emission properties of Q-carbon are attributed to (i) a unique sp2/sp3 mixture in Q-carbon, (ii) sp2-bonded highly conductive amorphous carbon-rich channels inside the Q-carbon cluster, (iii) a large local field enhancement due to the local geometry and microstructure of Q-carbon, and (iv) the presence of sp2-bonded amorphous carbon regions in the composite film. The temperature-dependent field emission properties, such as extreme sensitivity and an enhancement in the emission current density with temperature, can be explained by the local density of states near the Fermi level and the excellent thermal stability of the Q-carbon field emitters. From DFT simulation studies, the computed work function and the field-enhancement factor were determined to be 3.62 eV and ∼2300, respectively, which explains the excellent field emission characteristics of Q-carbon. The obtained field emission properties, in most cases, were superior to those from other carbon/diamond-based field emitters, which will open new frontiers in field emission-based electronic applications.
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Affiliation(s)
- Ariful Haque
- Electrical
Engineering, Ingram School of Engineering, Texas State University, San Marcos, Texas 78666, United States
- Materials
Science, Engineering & Commercialization Program, Texas State University, San Marcos, Texas 78666, United States
| | - Subrata Karmakar
- Electrical
Engineering, Ingram School of Engineering, Texas State University, San Marcos, Texas 78666, United States
| | - Ravi Kumar Trivedi
- High
Pressure & Synchroton Radiation Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - Brahmananda Chakraborty
- High
Pressure & Synchroton Radiation Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
- Homi
Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - Ravi Droopad
- Electrical
Engineering, Ingram School of Engineering, Texas State University, San Marcos, Texas 78666, United States
- Materials
Science, Engineering & Commercialization Program, Texas State University, San Marcos, Texas 78666, United States
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Sankaran KJ, Ficek M, Panda K, Yeh CJ, Sawczak M, Ryl J, Leou KC, Park JY, Lin IN, Bogdanowicz R, Haenen K. Boron-Doped Nanocrystalline Diamond-Carbon Nanospike Hybrid Electron Emission Source. ACS APPLIED MATERIALS & INTERFACES 2019; 11:48612-48623. [PMID: 31794182 DOI: 10.1021/acsami.9b17942] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Electron emission signifies an important mechanism facilitating the enlargement of devices that have modernized large parts of science and technology. Today, the search for innovative electron emission devices for imaging, sensing, electronics, and high-energy physics continues. Integrating two materials with dissimilar electronic properties into a hybrid material is an extremely sought-after synergistic approach, envisioning a superior field electron emission (FEE) material. An innovation is described regarding the fabrication of a nanostructured carbon hybrid, resulting from the one-step growth of boron-doped nanocrystalline diamond (BNCD) and carbon nanospikes (CNSs) by a microwave plasma-enhanced chemical vapor deposition technique. Spectroscopic and microscopic tools are used to investigate the morphological, bonding, and microstructural characteristics related to the growth mechanism of these hybrids. Utilizing the benefits of both the sharp edges of the CNSs and the high stability of BNCD, promising FEE performance with a lower turn-on field of 1.3 V/μm, a higher field enhancement factor of 6780, and a stable FEE current stability lasting for 780 min is obtained. The microplasma devices utilizing these hybrids as a cathode illustrate a superior plasma illumination behavior. Such hybrid carbon nanostructures, with superb electron emission characteristics, can encourage the enlargement of several electron emission device technologies.
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Affiliation(s)
| | - Mateusz Ficek
- Department of Metrology and Optoelectronics, Faculty of Electronics, Telecommunications and Informatics , Gdansk University of Technology , 11/12 G. Narutowicza Street , 80-233 Gdansk , Poland
| | - Kalpataru Panda
- Center for Nanomaterials and Chemical Reactions , Institute for Basic Science (IBS) , 34141 Daejeon , Korea
- Department of Chemistry , Korea Advanced Institute of Science and Technology (KAIST) , 34141 Daejeon , Korea
| | - Chien-Jui Yeh
- Department of Engineering and System Science , National Tsing Hua University , Hsinchu , 30013 Taiwan , Republic of China
| | - Miroslaw Sawczak
- Center for Plasma and Laser Engineering, The Szewalski Institute of Fluid Flow Machinery , Polish Academy of Sciences , Fiszera 14 , 80-231 Gdansk , Poland
| | - Jacek Ryl
- Department of Electrochemistry, Corrosion and Materials Engineering, Faculty of Chemistry , Gdansk University of Technology , Narutowicza 11/12 , 80-233 Gdansk , Poland
| | - Keh-Chyang Leou
- Department of Engineering and System Science , National Tsing Hua University , Hsinchu , 30013 Taiwan , Republic of China
| | - Jeong Young Park
- Center for Nanomaterials and Chemical Reactions , Institute for Basic Science (IBS) , 34141 Daejeon , Korea
- Department of Chemistry , Korea Advanced Institute of Science and Technology (KAIST) , 34141 Daejeon , Korea
| | - I-Nan Lin
- Department of Physics , Tamkang University , Tamsui , 251 Taiwan , Republic of China
| | - Robert Bogdanowicz
- Department of Metrology and Optoelectronics, Faculty of Electronics, Telecommunications and Informatics , Gdansk University of Technology , 11/12 G. Narutowicza Street , 80-233 Gdansk , Poland
| | - Ken Haenen
- Institute for Materials Research (IMO) , Hasselt University , 3590 Diepenbeek , Belgium
- IMOMEC, IMEC vzw , 3590 Diepenbeek , Belgium
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Sankaran KJ, Yeh CJ, Hsieh PY, Pobedinskas P, Kunuku S, Leou KC, Tai NH, Lin IN, Haenen K. Origin of Conductive Nanocrystalline Diamond Nanoneedles for Optoelectronic Applications. ACS APPLIED MATERIALS & INTERFACES 2019; 11:25388-25398. [PMID: 31260239 DOI: 10.1021/acsami.9b05469] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Microstructural evolution of nanocrystalline diamond (NCD) nanoneedles owing to the addition of methane and nitrogen in the reactant gases is systematically addressed. It has been determined that varying the concentration of CH4 in the CH4/H2/N2 plasma is significant to tailor the morphology and microstructure of NCD films. While NCD films grown with 1% CH4 in a CH4/H2/N2 (3%) plasma contain large diamond grains, the microstructure changed considerably for NCD films grown using 5% (or 10%) CH4, ensuing in nanosized diamond grains. For 15% CH4-grown NCD films, a well-defined nanoneedle structure evolves. These NCD nanoneedle films contain sp3 phase diamond, sheathed with sp2-bonded graphitic phases, achieving a low resistivity of 90 Ω cm and enhanced field electron emission (FEE) properties, namely, a low turn-on field of 4.3 V/μm with a high FEE current density of 3.3 mA/cm2 (at an applied field of 8.6 V/μm) and a significant field enhancement factor of 3865. Furthermore, a microplasma device utilizing NCD nanoneedle films as cathodes can trigger a gas breakdown at a low threshold field of 3600 V/cm attaining a high plasma illumination current density of 1.14 mA/cm2 at an applied voltage of 500 V, and a high plasma lifetime stability of 881 min is evidenced. The optical emission spectroscopy studies suggest that the C2, CN, and CH species in the growing plasma are the major causes for the observed microstructural evolution in the NCD films. However, the increase in substrate temperature to ∼780 °C due to the incorporation of 15% CH4 in the CH4/H2/N2 plasma is the key driver resulting in the origin of nanoneedles in NCD films. The outstanding optoelectronic characteristics of these nanoneedle films make them suitable as cathodes in high-brightness display panels.
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Affiliation(s)
| | | | | | - Paulius Pobedinskas
- Institute for Materials Research (IMO) , Hasselt University , Diepenbeek 3590 , Belgium
- IMOMEC, IMEC vzw , Diepenbeek 3590 , Belgium
| | | | | | | | - I-Nan Lin
- Department of Physics , Tamkang University , Tamsui 251 , Taiwan , Republic of China
| | - Ken Haenen
- Institute for Materials Research (IMO) , Hasselt University , Diepenbeek 3590 , Belgium
- IMOMEC, IMEC vzw , Diepenbeek 3590 , Belgium
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4
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Nickel oxide nanoparticles supported onto oriented multi-walled carbon nanotube as electrodes for electrochemical capacitors. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2018.12.102] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Sankaran KJ, Ficek M, Kunuku S, Panda K, Yeh CJ, Park JY, Sawczak M, Michałowski PP, Leou KC, Bogdanowicz R, Lin IN, Haenen K. Self-organized multi-layered graphene-boron-doped diamond hybrid nanowalls for high-performance electron emission devices. NANOSCALE 2018; 10:1345-1355. [PMID: 29296984 DOI: 10.1039/c7nr06774g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Carbon nanomaterials such as nanotubes, nanoflakes/nanowalls, and graphene have been used as electron sources due to their superior field electron emission (FEE) characteristics. However, these materials show poor stability and short lifetimes, which prevent their use in practical device applications. The aim of this study was to find an innovative nanomaterial possessing both high robustness and reliable FEE behavior. Herein, a hybrid structure of self-organized multi-layered graphene (MLG)-boron doped diamond (BDD) nanowall materials with superior FEE characteristics was successfully synthesized using a microwave plasma enhanced chemical vapor deposition process. Transmission electron microscopy reveals that the as-prepared carbon clusters have a uniform, dense, and sharp nanowall morphology with sp3 diamond cores encased by an sp2 MLG shell. Detailed nanoscale investigations conducted using peak force-controlled tunneling atomic force microscopy show that each of the core-shell structured carbon cluster fields emits electrons equally well. The MLG-BDD nanowall materials show a low turn-on field of 2.4 V μm-1, a high emission current density of 4.2 mA cm-2 at an applied field of 4.0 V μm-1, a large field enhancement factor of 4500, and prominently high lifetime stability (lasting for 700 min), which demonstrate the superiority of these materials over other hybrid nanostructured materials. The potential of these MLG-BDD hybrid nanowall materials in practical device applications was further illustrated by the plasma illumination behavior of a microplasma device with these materials as the cathode, where a low threshold voltage of 330 V (low threshold field of 330 V mm-1) and long plasma stability of 358 min were demonstrated. The fabrication of these hybrid nanowalls is straight forward and thereby opens up a pathway for the advancement of next-generation cathode materials for high brightness electron emission and microplasma-based display devices.
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Santra S, Das NS, Besra N, Banerjee D, Chattopadhyay KK. Graphene-Anchored p-Type CuBO 2 Nanocrystals for a Transparent Cold Cathode. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:9961-9971. [PMID: 28837774 DOI: 10.1021/acs.langmuir.7b01650] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
CuBO2 nanostructures were synthesized by employing a low-cost hydrothermal technique to combine into the CuBO2-RGO nanocomposite for the first time using chemically prepared graphene sheets. The nanohybrid samples were characterized for structural information using X-ray diffraction (XRD) that revealed the proper crystalline phase formation of CuBO2 unaltered by composite formation with graphene. Raman spectroscopic studies were employed to confirm the presence of graphene. A morphological study with field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) suggested the proper wrapping of RGO sheets over CuBO2 nanocubes. Moreover, the close proximity of lattice planes of CuBO2 and RGO to each other was observed in high-resolution TEM studies that were correlated with the Raman spectroscopic studies. Finally, the samples were characterized to study the field emission (FE) properties of the same using a laboratory-made high-vacuum field-emission setup. Finite-element-based theoretical simulation studies were carried out to explain and compare the field emission properties with the experimental results. The FE properties of the composite samples were found to be tuned by the nature of wrapping the RGO sheets over the CuBO2 nanocubes, which was typically dependent upon the spiky morphology of the nanocubes.
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Affiliation(s)
- S Santra
- Thin Film & Nanoscience Laboratory, Department of Physics and ‡School of Materials Science and Nanotechnology, Jadavpur University , Kolkata 700 032, India
| | - N S Das
- Thin Film & Nanoscience Laboratory, Department of Physics and ‡School of Materials Science and Nanotechnology, Jadavpur University , Kolkata 700 032, India
| | - N Besra
- Thin Film & Nanoscience Laboratory, Department of Physics and ‡School of Materials Science and Nanotechnology, Jadavpur University , Kolkata 700 032, India
| | - D Banerjee
- Thin Film & Nanoscience Laboratory, Department of Physics and ‡School of Materials Science and Nanotechnology, Jadavpur University , Kolkata 700 032, India
| | - K K Chattopadhyay
- Thin Film & Nanoscience Laboratory, Department of Physics and ‡School of Materials Science and Nanotechnology, Jadavpur University , Kolkata 700 032, India
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Saravanan A, Huang BR, Manoharan D, Lin IN. High-Performance Electron Field Emitters and Microplasma Cathodes Based on Conductive Hybrid Granular Structured Diamond Materials. ACS APPLIED MATERIALS & INTERFACES 2017; 9:4916-4925. [PMID: 28084726 DOI: 10.1021/acsami.6b12375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
High-performance diamond electron field emitters (EFEs) with extremely low turn-on field (E0 = 1.72 V/μm) and high current density (1.70 mA/cm2 at an applied field of 3.86 V/μm) were successfully synthesized by using a modified two-step microwave plasma chemical deposition process. Such emitters possess EFE properties comparable with most of carbon- or semiconductor-based EFE materials, but with markedly better lifetime stability. The superb EFE behavior of these materials was achieved owing to the reduction in the diamond-to-Si interfacial resistance and the increase in the conductivity of the bulk diamond films (HBD-400 V) via the applications of high bias voltage during the preparation of the ultrananocrystalline diamond (UNCD) primary layer and the subsequent plasma post-treatment (PPT) process, respectively. The superior EFE properties along with enhanced robustness of HBD-400 V films compared with the existing diamond-based EFE materials rendered these materials of greater potential for applications in high brightness display and multifunctional microplasma.
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Affiliation(s)
- Adhimoorthy Saravanan
- Graduate Institute of Electro-Optical Engineering and Department of Electronic and Computer Engineering, National Taiwan University of Science and Technology , Taipei 106, Taiwan, ROC
| | - Bohr-Ran Huang
- Graduate Institute of Electro-Optical Engineering and Department of Electronic and Computer Engineering, National Taiwan University of Science and Technology , Taipei 106, Taiwan, ROC
| | | | - I-Nan Lin
- Department of Physics, Tamkang University , Tamsui 251, Taiwan, ROC
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8
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Silva TA, Zanin H, Corat EJ, Fatibello-Filho O. Simultaneous Voltammetric Determination of Paracetamol, Codeine and Caffeine on Diamond-like Carbon Porous Electrodes. ELECTROANAL 2016. [DOI: 10.1002/elan.201600665] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Tiago Almeida Silva
- Department of Chemistry; Federal University of São Carlos; Rod. Washington Luís km 235 13560-970 São Carlos, SP Brazil
| | - Hudson Zanin
- Carbon Sci-Tech Labs; School of Electrical and Computer Engineering; University of Campinas; Av. Albert Einstein 400 13083-852 Campinas-SP Brazil
| | - Evaldo José Corat
- National Institute for Space Research; Av. dos Astronautas 1758 12227-010 São José dos Campos, SP Brazil
| | - Orlando Fatibello-Filho
- Department of Chemistry; Federal University of São Carlos; Rod. Washington Luís km 235 13560-970 São Carlos, SP Brazil
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Collins CM, Parmee RJ, Milne WI, Cole MT. High Performance Field Emitters. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2016; 3:1500318. [PMID: 27610335 PMCID: PMC5008108 DOI: 10.1002/advs.201500318] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 11/06/2015] [Indexed: 05/31/2023]
Abstract
The field electron emission performance of bulk, 1D, and 2D nanomaterials is here empirically compared in the largest metal-analysis of its type. No clear trends are noted between the turn-on electric field and maximum current density as a function of emitter work function, while a more pronounced correlation with the emitters dimensionality is noted. The turn-on field is found to be twice as large for bulk materials compared to 1D and 2D materials, empirically confirming the wider communities view that high aspect ratios, and highly perturbed surface morphologies allow for enhanced field electron emitters.
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Affiliation(s)
- Clare M Collins
- Department of Engineering Electrical Engineering Division University of Cambridge 9 JJ Thomson Avenue CB3 0FA Cambridge UK
| | - Richard J Parmee
- Department of Engineering Electrical Engineering Division University of Cambridge 9 JJ Thomson Avenue CB3 0FA Cambridge UK
| | - William I Milne
- Department of EngineeringElectrical Engineering DivisionUniversity of Cambridge9 JJ Thomson AvenueCB3 0FACambridgeUK; Quantum Nanoelectronics Research CentreTokyo Institute of Technology152-8550TokyoJapan
| | - Matthew T Cole
- Department of Engineering Electrical Engineering Division University of Cambridge 9 JJ Thomson Avenue CB3 0FA Cambridge UK
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Chang TH, Hsieh PY, Kunuku S, Lou SC, Manoharan D, Leou KC, Lin IN, Tai NH. High Stability Electron Field Emitters Synthesized via the Combination of Carbon Nanotubes and N₂-Plasma Grown Ultrananocrystalline Diamond Films. ACS APPLIED MATERIALS & INTERFACES 2015; 7:27526-27538. [PMID: 26600097 DOI: 10.1021/acsami.5b09778] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
An electron field emitter with superior electron field emission (EFE) properties and improved lifetime stability is being demonstrated via the combination of carbon nanotubes and the CH4/N2 plasma grown ultrananocrystalline diamond (N-UNCD) films. The resistance of the carbon nanotubes to plasma ion bombardment is improved by the formation of carbon nanocones on the side walls of the carbon nanotubes, thus forming strengthened carbon nanotubes (s-CNTs). The N-UNCD films can thus be grown on s-CNTs, forming N-UNCD/s-CNTs carbon nanocomposite materials. The N-UNCD/s-CNTs films possess good conductivity of σ = 237 S/cm and marvelous EFE properties, such as low turn-on field of (E0) = 3.58 V/μm with large EFE current density of (J(e)) = 1.86 mA/cm(2) at an applied field of 6.0 V/μm. Moreover, the EFE emitters can be operated under 0.19 mA/cm(2) for more than 350 min without showing any sign of degradation. Such a superior EFE property along with high robustness characteristic of these combination of materials are not attainable with neither N-UNCD films nor s-CNTs films alone. Transmission electron microscopic investigations indicated that the N-UNCD films contain needle-like diamond grains encased in a few layers of nanographitic phase, which enhanced markedly the transport of electrons in the N-UNCD films. Moreover, the needle-like diamond grains were nucleated from the s-CNTs without the necessity of forming the interlayer that facilitate the transport of electrons crossing the diamond-to-Si interface. Both these factors contributed to the enhanced EFE behavior of the N-UNCD/s-CNTs films.
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Affiliation(s)
- Ting-Hsun Chang
- Department of Materials Science and Engineering, National Tsing-Hua University , Hsinchu 300, Taiwan, R.O.C
| | - Ping-Yen Hsieh
- Department of Materials Science and Engineering, National Tsing-Hua University , Hsinchu 300, Taiwan, R.O.C
| | - Srinivasu Kunuku
- Department of Engineering and System Science, National Tsing-Hua University , Hsinchu 300, Taiwan, R.O.C
| | - Shiu-Cheng Lou
- Center for Measurement Standards, Industrial Technology Research Institute , Hsinchu 300, Taiwan, R.O.C
| | - Divinah Manoharan
- Department of Physics, Tamkang University , New Taipei City 251, Taiwan, R.O.C
| | - Keh-Chyang Leou
- Department of Engineering and System Science, National Tsing-Hua University , Hsinchu 300, Taiwan, R.O.C
| | - I-Nan Lin
- Department of Physics, Tamkang University , New Taipei City 251, Taiwan, R.O.C
| | - Nyan-Hwa Tai
- Department of Materials Science and Engineering, National Tsing-Hua University , Hsinchu 300, Taiwan, R.O.C
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Sankaran KJ, Huang BR, Saravanan A, Manoharan D, Tai NH, Lin IN. Heterogranular-Structured Diamond-Gold Nanohybrids: A New Long-Life Electronic Display Cathode. ACS APPLIED MATERIALS & INTERFACES 2015; 7:27078-27086. [PMID: 26600002 DOI: 10.1021/acsami.5b10569] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In the age of hand-held portable electronics, the need for robust, stable and long-life cathode materials has become increasingly important. Herein, a novel heterogranular-structured diamond-gold nanohybrids (HDG) as a long-term stable cathode material for field-emission (FE) display and plasma display devices is experimentally demonstrated. These hybrid materials are electrically conductive that perform as an excellent field emitters, viz. low turn-on field of 2.62 V/μm with high FE current density of 4.57 mA/cm(2) (corresponding to a applied field of 6.43 V/μm) and prominently high lifetime stability lasting for 1092 min revealing their superiority on comparison with the other commonly used field emitters such as carbon nanotubes, graphene, and zinc oxide nanorods. The process of fabrication of these HDG materials is direct and easy thereby paving way for the advancement in next generation cathode materials for high-brightness FE and plasma-based display devices.
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Affiliation(s)
- Kamatchi Jothiramalingam Sankaran
- Department of Materials Science and Engineering, National Tsing Hua University , Hsinchu 300, Taiwan, R.O.C
- Institute for Materials Research (IMO), Hasselt University , 3590 Diepenbeek, Belgium
| | - Bohr-Ran Huang
- Graduate Institute of Electro-Optical Engineering and Department of Electronic Engineering, National Taiwan University of Science and Technology , Taipei 106, Taiwan, R.O.C
| | - Adhimoorthy Saravanan
- Graduate Institute of Electro-Optical Engineering and Department of Electronic Engineering, National Taiwan University of Science and Technology , Taipei 106, Taiwan, R.O.C
| | - Divinah Manoharan
- Department of Physics, Tamkang University , Tamsui 251, Taiwan, R.O.C
| | - Nyan-Hwa Tai
- Department of Materials Science and Engineering, National Tsing Hua University , Hsinchu 300, Taiwan, R.O.C
| | - I-Nan Lin
- Department of Physics, Tamkang University , Tamsui 251, Taiwan, R.O.C
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Kim M, Rho J. Metamaterials and imaging. NANO CONVERGENCE 2015; 2:22. [PMID: 28191408 DOI: 10.1186/s40580-014-0034-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 06/22/2015] [Indexed: 05/23/2023]
Abstract
Resolution of the conventional lens is limited to half the wavelength of the light source by diffraction. In the conventional optical system, evanescent waves, which carry sub-diffraction spatial information, has exponentially decaying amplitude and therefore cannot reach to the image plane. New optical materials called metamaterials have provided new ways to overcome diffraction limit in imaging by controlling the evanescent waves. Such extraordinary electromagnetic properties can be achieved and controlled through arranging nanoscale building blocks appropriately. Here, we review metamaterial-based lenses which offer the new types of imaging components and functions. Perfect lens, superlenses, hyperlenses, metalenses, flat lenses based on metasurfaces, and non-optical lenses including acoustic hyperlens are described. Not all of them offer sub-diffraction imaging, but they provide new imaging mechanisms by controlling and manipulating the path of light. The underlying physics, design principles, recent advances, major limitations and challenges for the practical applications are discussed in this review.
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Affiliation(s)
- Minkyung Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 790-784 Republic of Korea
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 790-784 Republic of Korea ; Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 790-784 Republic of Korea
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Kundu S, Dwivedi N, Satyanarayana N, Yeo RJ, Ahner J, Jones PM, Bhatia CS. Probing the role of carbon microstructure on the thermal stability and performance of ultrathin (<2 nm) overcoats on L10 FePt media for heat-assisted magnetic recording. ACS APPLIED MATERIALS & INTERFACES 2015; 7:158-165. [PMID: 25485473 DOI: 10.1021/am5054724] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
An understanding of the factors influencing the thermal stability of ultrathin carbon overcoats (COCs) is crucial for their application in heat-assisted magnetic recording (HAMR) at densities ≥ 1 Tb/in(2). Two types of non-hydrogenated ultrathin (∼1.5 nm) COCs were investigated after being subjected to laser-induced localized heating (at temperatures > 700 K) as envisaged in HAMR. Filtered cathodic vacuum arc (FCVA)-processed carbon with tuned C(+) ion energies of 350 eV followed by 90 eV provides significantly higher sp(3) C-C hybridization than magnetron sputter deposition even at very low thicknesses of ∼1.5 nm. As a result, the FCVA-deposited ultrathin carbon overcoats displayed excellent thermal stability along with improved wear and corrosion resistance. On the other hand, the sputtered carbon exhibited carbon loss and topographical and structural changes after laser irradiation owing to lower sp(3) hybridization. Therefore, this study highlights the pivotal role of carbon microstructure, primarily sp(3) hybridization, in non-hydrogenated carbon overcoats to maintain excellent thermal stability during the recurring high-temperature cycles in a HAMR process.
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Affiliation(s)
- Shreya Kundu
- Department of Electrical and Computer Engineering, National University of Singapore , 21 Lower Kent Ridge Road, Singapore 117583, Republic of Singapore
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Silva TA, Zanin H, May PW, Corat EJ, Fatibello-Filho O. Electrochemical performance of porous diamond-like carbon electrodes for sensing hormones, neurotransmitters, and endocrine disruptors. ACS APPLIED MATERIALS & INTERFACES 2014; 6:21086-21092. [PMID: 25402230 DOI: 10.1021/am505928j] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Porous diamond-like carbon (DLC) electrodes have been prepared, and their electrochemical performance was explored. For electrode preparation, a thin DLC film was deposited onto a densely packed forest of highly porous, vertically aligned multiwalled carbon nanotubes (VACNT). DLC deposition caused the tips of the carbon nanotubes to clump together to form a microstructured surface with an enlarged surface area. DLC:VACNT electrodes show fast charge transfer, which is promising for several electrochemical applications, including electroanalysis. DLC:VACNT electrodes were applied to the determination of targeted molecules such as dopamine (DA) and epinephrine (EP), which are neurotransmitters/hormones, and acetaminophen (AC), an endocrine disruptor. Using simple and low-cost techniques, such as cyclic voltammetry, analytical curves in the concentration range from 10 to 100 μmol L(-1) were obtained and excellent analytical parameters achieved, including high analytical sensitivity, good response stability, and low limits of detection of 2.9, 4.5, and 2.3 μmol L(-1) for DA, EP, and AC, respectively.
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Affiliation(s)
- Tiago A Silva
- Department of Chemistry, Federal University of São Carlos , Rodovia Washington Luís km 235, 676, São Carlos, 13560-970, SP Brazil
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Deng JH, Cheng L, Wang FJ, Li GZ, Li DJ, Cheng GA. High current density and longtime stable field electron transfer from large-area densely arrayed graphene nanosheet-carbon nanotube hybrids. ACS APPLIED MATERIALS & INTERFACES 2014; 6:21558-21566. [PMID: 25335851 DOI: 10.1021/am5065624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Achieving high current and longtime stable field emission from large area (larger than 1 mm(2)), densely arrayed emitters is of great importance in applications for vacuum electron sources. We report here the preparation of graphene nanosheet-carbon nanotube (GNS-CNT) hybrids by following a process of iron ion prebombardment on Si wafers, catalyst-free growth of GNSs on CNTs, and high-temperature annealing. Structural observations indicate that the iron ion prebombardment influences the growth of CNTs quite limitedly, and the self-assembled GNSs sparsely distributed on the tips of CNTs with their sharp edges unfolded outside. The field emission study indicates that the maximum emission current density (Jmax) is gradually promoted after these treatments, and the composition with GNSs is helpful for decreasing the operation fields of CNTs. An optimal Jmax up to 85.10 mA/cm(2) is achieved from a 4.65 mm(2) GNS-CNT sample, far larger than 7.41 mA/cm(2) for the as-grown CNTs. This great increase of Jmax is ascribed to the reinforced adhesion of GNS-CNT hybrids to substrates. We propose a rough calculation and find that this adhesion is promoted by 7.37 times after the three-step processing. We consider that both the ion prebombardment produced rough surface and the wrapping of CNT foot by catalyst residuals during thermal processing are responsible for this enhanced adhesion. Furthermore, the three-step prepared GNS-CNT hybrids present excellent field emission stability at high emission current densities (larger than 20 mA/cm(2)) after being perfectly aged.
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Affiliation(s)
- Jian-Hua Deng
- College of Physics and Materials Science, Tianjin Normal University , Tianjin 300387, People's Republic of China
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Hung YJ, Huang YJ, Chang HC, Lee KY, Lee SL. Patterned growth of carbon nanotubes over vertically aligned silicon nanowire bundles for achieving uniform field emission. NANOSCALE RESEARCH LETTERS 2014; 9:540. [PMID: 25298758 PMCID: PMC4189046 DOI: 10.1186/1556-276x-9-540] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 09/10/2014] [Indexed: 05/28/2023]
Abstract
A fabrication strategy is proposed to enable precise coverage of as-grown carbon nanotube (CNT) mats atop vertically aligned silicon nanowire (VA-SiNW) bundles in order to realize a uniform bundle array of CNT-SiNW heterojunctions over a large sample area. No obvious electrical degradation of as-fabricated SiNWs is observed according to the measured current-voltage characteristic of a two-terminal single-nanowire device. Bundle arrangement of CNT-SiNW heterojunctions is optimized to relax the electrostatic screening effect and to maximize the field enhancement factor. As a result, superior field emission performance and relatively stable emission current over 12 h is obtained. A bright and uniform fluorescent radiation is observed from CNT-SiNW-based field emitters regardless of its bundle periodicity, verifying the existence of high-density and efficient field emitters on the proposed CNT-SiNW bundle arrays.
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Affiliation(s)
- Yung-Jr Hung
- Department of Photonics, National Sun Yat-sen University, No. 70, Lienhai Rd., Kaohsiung 80424, Taiwan
| | - Yung-Jui Huang
- Department of Electronic Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan
| | - Hsuan-Chen Chang
- Department of Electronic Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan
| | - Kuei-Yi Lee
- Department of Electronic Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan
| | - San-Liang Lee
- Department of Electronic Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan
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Sridhar S, Tiwary C, Vinod S, Taha-Tijerina JJ, Sridhar S, Kalaga K, Sirota B, Hart AHC, Ozden S, Sinha RK, Vajtai R, Choi W, Kordás K, Ajayan PM. Field emission with ultralow turn on voltage from metal decorated carbon nanotubes. ACS NANO 2014; 8:7763-7770. [PMID: 25054222 DOI: 10.1021/nn500921s] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A simple and scalable method of decorating 3D-carbon nanotube (CNT) forest with metal particles has been developed. The results observed in aluminum (Al) decorated CNTs and copper (Cu) decorated CNTs on silicon (Si) and Inconel are compared with undecorated samples. A significant improvement in the field emission characteristics of the cold cathode was observed with ultralow turn on voltage (Eto ∼ 0.1 V/μm) due to decoration of CNTs with metal nanoparticles. Contact resistance between the CNTs and the substrate has also been reduced to a large extent, allowing us to get stable emission for longer duration without any current degradation, thereby providing a possibility of their use in vacuum microelectronic devices.
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Affiliation(s)
- Srividya Sridhar
- Department of Applied Physics, Delhi Technological University (Formerly Delhi College of Engineering) , Bawana Road, Delhi 110042, India
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Zanin H, Margraf-Ferreira A, da Silva N, Marciano F, Corat E, Lobo A. Graphene and carbon nanotube composite enabling a new prospective treatment for trichomoniasis disease. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2014; 41:65-9. [DOI: 10.1016/j.msec.2014.04.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 01/23/2014] [Accepted: 04/07/2014] [Indexed: 01/13/2023]
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Hollanda L, Lobo A, Lancellotti M, Berni E, Corat E, Zanin H. Graphene and carbon nanotube nanocomposite for gene transfection. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2014; 39:288-98. [DOI: 10.1016/j.msec.2014.03.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 01/26/2014] [Accepted: 03/01/2014] [Indexed: 01/08/2023]
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Zanin H, May PW, Fermin DJ, Plana D, Vieira SMC, Milne WI, Corat EJ. Porous boron-doped diamond/carbon nanotube electrodes. ACS APPLIED MATERIALS & INTERFACES 2014; 6:990-995. [PMID: 24392640 DOI: 10.1021/am4044344] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Nanostructuring boron-doped diamond (BDD) films increases their sensitivity and performance when used as electrodes in electrochemical environments. We have developed a method to produce such nanostructured, porous electrodes by depositing BDD thin film onto a densely packed "forest" of vertically aligned multiwalled carbon nanotubes (CNTs). The CNTs had previously been exposed to a suspension of nanodiamond in methanol causing them to clump together into "teepee" or "honeycomb" structures. These nanostructured CNT/BDD composite electrodes have been extensively characterized by scanning electron microscopy, Raman spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. Not only do these electrodes possess the excellent, well-known characteristics associated with BDD (large potential window, chemical inertness, low background levels), but also they have electroactive areas and double-layer capacitance values ∼450 times greater than those for the equivalent flat BDD electrodes.
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Affiliation(s)
- H Zanin
- School of Chemistry, University of Bristol , Bristol BS8 1TS, United Kingdom
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