A way to improve the uniformity of nanometer-thickness graphite film synthesized on polycrystalline Ni substrate: From large grain to small grain

Hu, Qicheng; Kim, Seul-Gi; Nam, Ki-Bong; Yeo, Jin-Ho; Kim, Taesung; Kim, Mun-Ja; Yoo, Jinsu

doi:10.1016/j.carbon.2018.12.044

Cited by 16 publications

(12 citation statements)

References 23 publications

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“…Methods such as the molten flux route (>1500 °C) − or the metal–carbon solid solution route − have been explored to synthesize graphite crystals in the bulk form or as thin films. However, the graphite films generated are often heavily wrinkled, a defect that, along with grain boundaries, dislocations, and vacancies, is largely detrimental to their properties, including thermal and electrical conductivities and mechanical properties.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Highly Oriented Graphite Films with a Low Wrinkle Density and Near-Millimeter-Scale Lateral Grains

et al. 2020

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Principal defects found in graphite films include grain boundaries and wrinkles. These defects are well known to have detrimental effects on properties such as thermal and electrical conductivities as well as mechanical properties. With a two-fold objective of synthesizing graphite films with large single crystal grains and no wrinkles, we have developed a relatively low temperature (< 1150 °C) process that involves the precipitation of graphite films from nickel-carbon solid solutions followed by in-situ etching of the nickel foil substrates with anhydrous chlorine gas to obtain near wrinkle free continuous graphite films. The size (La) distribution of lateral grains (or single crystal regions) in these highly oriented graphite films has been found to be asymmetric with the largest grains about 0.9 mm in diameter, as determined by electron backscatter diffraction (EBSD). Thus, the growth of large area graphite films with grains much larger than those reported for highly oriented pyrolytic graphite (HOPG, ~20-30 µm), and with a low density of wrinkles, as in the case of HOPG, but prepared at much lower temperatures, is reported here.

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Section: Introductionmentioning

confidence: 99%

Synthesis of Highly Oriented Graphite Films with a Low Wrinkle Density and Near-Millimeter-Scale Lateral Grains

et al. 2020

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“…Chemical vapor deposition (CVD) is an alternative approach to synthesize graphite film with high crystallinity. It has been demonstrated that the graphite film can be grown on many transition metals (Pt, Ni, ,− ,− Co, Cu) by catalytic decomposition of gaseous hydrocarbons, such as CH 4 , C 2 H 2 , and C 2 H 4 . Although only a moderate temperature (700–1300 °C) is required in CVD, it typically takes a few hours to synthesize a nanometer-thick film even conducted under vacuum atmosphere. ,, …”

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confidence: 99%

Second Time-Scale Synthesis of High-Quality Graphite Films by Quenching for Effective Electromagnetic Interference Shielding

Zhou

Liu

et al. 2020

ACS Nano

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Graphite film has many remarkable properties and intriguing applications from energy storage, electromagnetic interference (EMI) shielding, and thermal management to ultraviolet lithography. However, the existing synthesis methods require an extremely high processing temperature of ∼3000 °C and/or long processing time of typically hours. Here, we report an ultrafast synthesis of tens of nanometer-thick high-quality graphite films within a few seconds by quenching a hot Ni foil in ethanol. The vertical growth rate can reach over 64 nm s −1 , which is more than 2 orders of magnitude higher than those of the existing methods. Moreover, the films show excellent electrical conductivity (∼2.6 × 10 5 S/m) and mechanical strength (∼110 MPa) comparable to or even better than those synthesized by chemical vapor deposition. As an example, we demonstrate the potential of these graphite films for effective EMI shielding, which show a record absolute shielding effectiveness of 481,000 dB cm 2 g −1 , outperforming all the reported synthetic materials.

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“…Fine-tuning the substrate’s surface roughness, annealing time (grain size) 30 , 47 and precipitation control 43 would help in reducing the areal NGF thickness uniformity down to µm 2 and/or even nm 2 scale (i.e., with thickness variations of a few nanometers). To control substrate surface roughness, techniques such as electropolishing of the as received Ni foils could be considered 48 .…”

Section: Resultsmentioning

confidence: 99%

Semi-transparent graphite films growth on Ni and their double-sided polymer-free transfer

Deokar

Genovese

Surya

et al. 2020

Sci Rep

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Nanorange thickness graphite films (NGFs) are robust nanomaterials that can be produced via catalytic chemical vapour deposition but questions remain regarding their facile transfer and how surface topography may affect their application in next-generation devices. Here, we report the growth of NGFs (with an area of 55 cm2 and thickness of ~ 100 nm) on both sides of a polycrystalline Ni foil and their polymer-free transfer (front- and back-side, in areas up to 6 cm2). Due to the catalyst foil topography, the two carbon films differed in physical properties and other characteristics such as surface roughness. We demonstrate that the coarser back-side NGF is well-suited for NO2 sensing, whereas the smoother and more electrically conductive front-side NGF (2000 S/cm, sheet resistance − 50 Ω/sq) could be a viable conducting channel or counter electrode in solar cells (as it transmits 62% of visible light). Overall, the growth and transfer processes described could help realizing NGFs as an alternative carbon material for those technological applications where graphene and micrometer-thick graphite films are not an option.

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A way to improve the uniformity of nanometer-thickness graphite film synthesized on polycrystalline Ni substrate: From large grain to small grain

Cited by 16 publications

References 23 publications

Synthesis of Highly Oriented Graphite Films with a Low Wrinkle Density and Near-Millimeter-Scale Lateral Grains

Synthesis of Highly Oriented Graphite Films with a Low Wrinkle Density and Near-Millimeter-Scale Lateral Grains

Second Time-Scale Synthesis of High-Quality Graphite Films by Quenching for Effective Electromagnetic Interference Shielding

Semi-transparent graphite films growth on Ni and their double-sided polymer-free transfer

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