scholarly journals Waste NR Latex Based-Precursors as Carbon Source for CNTs Eco-Fabrications

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3409
Author(s):  
Mohd Adib Hazan ◽  
Kar Fei Chan ◽  
Khairun Afiqa Jofri ◽  
Md Shuhazlly Mamat ◽  
Nor Azam Endot ◽  
...  
Keyword(s):  
Carbon Source ◽  
Vapor Deposition ◽  
Value Added ◽  
Chemical Vapor ◽  
Hydrocarbon Chain ◽  
Rubber Glove ◽  
Gas Chromatography Mass Spectroscopy ◽  
Long Chain ◽  
Better Than

In this work, the potential of utilizing a waste latex-based precursor (i.e., natural rubber glove (NRG)) as a carbon source for carbon nanotube (CNT) fabrication via chemical vapor deposition has been demonstrated. Gas chromatography-mass spectroscopy (GC-MS) analysis reveals that the separation of the lightweight hydrocarbon chain from the heavier long chain differs in hydrocarbon contents in the NRG fraction (NRG-L). Both solid NRG (NRG-S) and NRG-L samples contain >63% carbon, <0.6% sulfur and <0.08% nitrogen content, respectively, as per carbon-nitrogen-sulfur (CNS) analysis. Growth of CNTs on the samples was confirmed by Raman spectra, SEM and TEM images, whereby it was shown that NRG-S is better than NRG-L in terms of synthesized CNTs yield percentage with similar quality. The optimum vaporization and reaction temperatures were 350 and 800 °C, respectively, considering the balance of good yield percentage (26.7%) and quality of CNTs (ID/IG = 0.84 ± 0.08, diameter ≈ 122 nm) produced. Thus, utilization of waste NRG as a candidate for carbon feedstock to produce value-added CNTs products could be a significant approach for eco-technology.

The Cooling Rate Effect on Graphene Synthesis Using Low Pressure Chemical Vapor Deposition

2021 ◽  
Author(s):  
Byoungdo Lee ◽  
Weishen Chu ◽  
Wei Li
Keyword(s):  
Chemical Vapor Deposition ◽  
Reaction Time ◽  
Carbon Source ◽  
Cooling Rate ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Feeding Time ◽  
Process Variables ◽  
Pressure Chemical

Abstract Low-pressure chemical vapor deposition (LPCVD) is the most efficient method to synthesize large-scale, high-quality graphene for many potential applications such as flexible electronics, solar cells, and separation membranes. The quality of LPCVD is affected by process variables including methane/hydrogen (CH4/H2) ratio, time, pressure, temperature, and cooling rate. The cooling rate has been recognized as one of the most important process variables affecting the amount of carbon source, nucleation, reaction time, and thus the quality of the LPCVD. In this research, we investigate the effect of cooling rate on the quality of graphene synthesize by changing the cooling rate and the gas feeding time. Graphene coverage is measured by Raman mapping. It is found that fast cooling rate leads to decreased carbon source reaction time, which in turn results in higher coverage by monolayer graphene. The temperature-dependent gas feeding time corresponding to different cooling rates can be used to properly supply the carbon source onto the copper surface, also leading to a higher graphene coverage.

scholarly journals Structural and Magnetic Properties of Ni81Fe19Thin Film Grown on Si(001) Substrate via Single Graphene Layer

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Gui-fang Li ◽  
Shibin Liu ◽  
Shanglin Yang ◽  
Yongqian Du
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Vapor Deposition ◽  
Graphene Layer ◽  
Structural Investigation ◽  
Annealing Temperature ◽  
Chemical Vapor ◽  
Magnetic Thin Films ◽  
Structural And Magnetic Properties

We prepared magnetic thin films Ni81Fe19on single-crystal Si(001) substrates via single graphene layer through magnetron sputtering for Ni81Fe19and chemical vapor deposition for graphene. Structural investigation showed that crystal quality of Ni81Fe19thin films was significantly improved with insertion of graphene layer compared with that directly grown on Si(001) substrate. Furthermore, saturation magnetization of Ni81Fe19/graphene/Si(001) heterostructure increased to 477 emu/cm3with annealing temperatureTa=400°C, which is much higher than values of Ni81Fe19/Si(001) heterostructures withTaranging from 200°C to 400°C.

Experimental Study of the Effect of Precursor Composition On the Microstructure of Gallium Nitride Thin Films Grown by the MOCVD Process

2021 ◽  
Author(s):  
Omar D. Jumaah ◽  
Yogesh Jaluria
Keyword(s):  
Thin Films ◽  
Gallium Nitride ◽  
Chemical Vapor Deposition ◽  
Deposition Rate ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Transport Processes ◽  
Carrier Gas ◽  
Precursor Composition

Abstract Chemical vapor deposition (CVD) is a widely used manufacturing process for obtaining thin films of materials like silicon, silicon carbide, graphene and gallium nitride that are employed in the fabrication of electronic and optical devices. Gallium nitride (GaN) thin films are attractive materials for manufacturing optoelectronic device applications due to their wide band gap and superb optoelectronic performance. The reliability and durability of the devices depend on the quality of the thin films. The metal-organic chemical vapor deposition (MOCVD) process is a common technique used to fabricate high-quality GaN thin films. The deposition rate and uniformity of thin films are determined by the thermal transport processes and chemical reactions occurring in the reactor, and are manipulated by controlling the operating conditions and the reactor geometrical configuration. In this study, the epitaxial growth of GaN thin films on sapphire (AL2O3) substrates is carried out in two commercial MOCVD systems. This paper focuses on the composition of the precursor and the carrier gases, since earlier studies have shown the importance of precursor composition. The results show that the flow rate of trimethylgallium (TMG), which is the main ingredient in the process, has a significant effect on the deposition rate and uniformity of the films. Also the carrier gas plays an important role in deposition rate and uniformity. Thus, the use of an appropriate mixture of hydrogen and nitrogen as the carrier gas can improve the deposition rate and quality of GaN thin films.

Single and Few-Layer MoS2: CVD Synthesis, Transference, and Photodetection Application

MRS Advances ◽  
2017 ◽  
Vol 2 (60) ◽  
pp. 3709-3714
Author(s):  
Gustavo A. Saenz ◽  
Carlos de Anda Orea ◽  
Anupama B. Kaul
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Flexible Substrate ◽  
Synthesis Method ◽  
Chemical Vapor ◽  
Synthesis Methods ◽  
Phase Reaction ◽  
Isolation And Characterization ◽  
Cvd Synthesis

ABSTRACTTwo-dimensional layered materials, materials with weak out-of-plane van der Waals bonding and strong in-plane covalent bonding, have attracted special attention in recent years since the isolation and characterization of monolayer graphite, the graphene. The electrical bandgap in Transition Metal Di-Chalcogenides (TMDCs), non-existent in graphene, make them a good alternative family of materials for novel electronic and optoelectronic applications. 2H- MoS2, one of the most stable TMDCs, has been extensively studied, including the synthesis methods, and its potential applications in photodetection. The chemical vapor deposition (CVD) synthesis method has increased its potential over the years. The advantages of this method are scalability compared to micromechanical exfoliation, common process used in research laboratories, and the maintenance of the quality and intrinsic properties of the material compared to the liquid exfoliation methods. In this work, we synthesized high quality pristine 2H-MoS2 via atmospheric pressure chemical vapor deposition (APCVD) by vapor phase reaction of MoO3 and S powder precursors. The samples were characterized via Raman and photoluminescence (PL) spectroscopy and compared to mechanically exfoliated MoS2 crystal by measuring the full-width half maxima (FWHM) of monolayer and few-layer mesoscopic flakes. In addition, the CVD synthesized single and few-layered MoS2 domains were transferred to different substrates using a high yield process, including a flexible substrate, preserving the quality of the material. Finally, and mechanically exfoliated MoS2 two-terminal photodetector was designed, fabricated, and measured. Demonstrating thus the capability of heterostructure fabrication and the quality of our synthesis and device fabrication process.

Study of the quality of carbon nanotubes produced by chemical vapor deposition

2017 ◽  
Vol 90 (9) ◽  
pp. 1484-1487
Author(s):  
A. N. Krasnovskii ◽  
P. S. Kishchuk ◽  
T. M. Mukhin
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor

scholarly journals Chemical Vapor Deposition of IrTe2 Thin Films

Crystals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 575
Author(s):  
Rui Zhou ◽  
Zhaoyang Zhao ◽  
Juanxia Wu ◽  
Liming Xie
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Hexagonal Boron Nitride ◽  
Chemical Vapor ◽  
Spectroscopic Characterization ◽  
Electrical Measurement ◽  
Charge Ordering ◽  
Temperature Dependent ◽  
Raman Spectroscopic

Two-dimensional (2D) IrTe2 has a profound charge ordering and superconducting state, which is related to its thickness and doping. Here, we report the chemical vapor deposition (CVD) of IrTe2 films using different Ir precursors on different substrates. The Ir(acac)3 precursor and hexagonal boron nitride (h-BN) substrate is found to yield a higher quality of polycrystalline IrTe2 films. Temperature-dependent Raman spectroscopic characterization has shown the q1/8 phase to HT phase at ~250 K in the as-grown IrTe2 films on h-BN. Electrical measurement has shown the HT phase to q1/5 phase at around 220 K.

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