Plasma-electric field controlled growth of oriented graphene for energy storage applications

Ghosh, Subrata; Polaki, S. R.; Kamruddin, M.; Jeong, Sang Mun; Ostrikov, Kostya Ken

doi:10.1088/1361-6463/aab130

Cited by 25 publications

(26 citation statements)

References 63 publications

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“…Exemplifying Raman spectra for PECVD-grown monolayer graphene sheet and GNSPs are shown in Figure 2.1(a) and Figure 3.1(g), respectively. Generally the Raman spectra of pristine graphene monolayer do not include the D-band, whereas the Raman spectra of GNSPs and of all VG-GNs always include a D-band due to many exposed edges in the nanostructures [61,173]. We further note that the ratio of the 2D-band to G-band, (I 2D /I G ), is an important identifier of graphene quality.…”

Section: Characterizationmentioning

confidence: 87%

Single-step growth of graphene and graphene-based nanostructures by plasma-enhanced chemical vapor deposition

et al. 2019

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The realization of many promising technological applications of graphene and graphenebased nanostructures depends on the availability of reliable, scalable, high-yield and low-cost synthesis methods. Plasma enhanced chemical vapor deposition (PECVD) has been a versatile technique for synthesizing many carbon-based materials, because PECVD provides a rich chemical environment, including a mixture of radicals, molecules and ions from hydrocarbon precursors, which enables graphene growth on a variety of material surfaces at lower temperatures and faster growth than typical thermal chemical vapor deposition (T-CVD). Here we review recent advances in the PECVD techniques for synthesis of various graphene and graphene-based nanostructures, including horizontal growth of monolayer and multilayer graphene sheets, vertical growth of graphene nanostructures (VG-GNs) such as graphene nanostripes (GNSPs) with large aspect ratios, direct and selective deposition of monolayer and multi-layer graphene on nanostructured substrates, and growth of multi-wall carbon nanotubes (MWCNTs). By properly controlling the gas environment of the plasma, it is found that no active heating is necessary for the PECVD growth processes, and that highyield growth can take place in a single step on a variety of surfaces, including metallic, semiconducting and insulating materials. Phenomenological understanding of the growth mechanisms are described. Finally, challenges and promising outlook for further development in the PECVD techniques for graphene-based applications are discussed.

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Section: Characterizationmentioning

confidence: 87%

Single-step growth of graphene and graphene-based nanostructures by plasma-enhanced chemical vapor deposition

et al. 2019

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“…Another graphite piece was placed just below the heater, and the direct current (DC) plasma was ignited between these two electrodes. However, our growth parameters were not tuned in favor of vertical graphene formation [23], but rather adjusted towards thin film growth. Figure 1c is a photograph taken during the growth phase (side view, the samples on the heater are seen to be immersed in the glowing plasma).…”

Section: Methodsmentioning

confidence: 99%

Transfer-Free Graphene-Like Thin Films on GaN LED Epiwafers Grown by PECVD Using an Ultrathin Pt Catalyst for Transparent Electrode Applications

et al. 2019

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In this work, we grew transfer-free graphene-like thin films (GLTFs) directly on gallium nitride (GaN)/sapphire light-emitting diode (LED) substrates. Their electrical, optical and thermal properties were studied for transparent electrode applications. Ultrathin platinum (2 nm) was used as the catalyst in the plasma-enhanced chemical vapor deposition (PECVD). The growth parameters were adjusted such that the high temperature exposure of GaN wafers was reduced to its minimum (deposition temperature as low as 600 °C) to ensure the intactness of GaN epilayers. In a comparison study of the Pt-GLTF GaN LED devices and Pt-only LED devices, the former was found to be superior in most aspects, including surface sheet resistance, power consumption, and temperature distribution, but not in optical transmission. This confirmed that the as-developed GLTF-based transparent electrodes had good current spreading, current injection and thermal spreading functionalities. Most importantly, the technique presented herein does not involve any material transfer, rendering a scalable, controllable, reproducible and semiconductor industry-compatible solution for transparent electrodes in GaN-based optoelectronic devices.

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“…We note that the electric field from the plasma sheath perpendicular to the substrate affects the growth direction of the graphene sheets. [ 29 ] Furthermore, we recognize that the radio‐frequency (typically 13.56 MHz) plasma can be stabilized over extended volume over long‐range propagation, with the assistance of streamlined magnetic field. Such plasma enhancement using streamlined magnetic field enables high plasma density with uniformly distributed ion energy without decay over extended space, which is essential for deposition of crystalline 2D carbon materials free of external heating and thus offers an energy‐efficient means for large‐scale production of graphene films.…”

Section: Introductionmentioning

confidence: 99%

“…Many efforts have been made to focus on the control of the plasma power, [ 15,25,31 ] plasma distribution, [ 32,33 ] and sample direction [ 29 ] to optimize the thermodynamic and/or kinetic aspects of nucleation and growth of VSG and to deepen understanding of the growth mechanism. It has been reported recently that meso‐plasma CVD with RF power unit can efficiently modulate the film structure with an extremely high growth rate, [ 34 ] nevertheless the sample dimension was very small and temperature of the local substrate during the growth process was not clear.…”

Section: Introductionmentioning

confidence: 99%

Heater‐Free and Substrate‐Independent Growth of Vertically Standing Graphene Using A High‐Flux Plasma‐Enhanced Chemical Vapor Deposition

Zhang

Shen

et al. 2020

Adv Materials Inter

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Graphene, a typical 2D nanostructure comprising of sp 2hybridized carbon atoms offers not only superior electron mobility and mechanical strength, but also huge specific surface area and facile functionalization. [4,5] All these merits render the vast utilizations of graphene in optoelectronics, [6,7] FETs, [8,9] sensors, [10] catalysts [11] and energy storage devices. [12,13] Compared with the laid-down graphene, vertically standing graphene (VSG) is composed of folded graphene petals with seamless edges [14] growing nearly perpendicularly to the substrate regardless of catalyst surface. [15-17] The tremendous interests toward VSG stem from its unique properties, such as large surface to volume ratio, nonaggregation morphology, and abundance of exposed and ultrathin edges. [18,19] Along with the excellent intrinsic properties of graphene, VSG exhibits its indispensable roles especially in the fields of emitters, [20] supercapacitors, [21] and fuel cells. [22] Notably, the morphologies and structural features of VSG significantly influences such applications. [12,21] However, conventional deposition processes for VSG are usually carried out above 500 °C [15,21,23-25] with the usual drawback of poor scalability, [26,27] which hampers both scientific research and large scale fabrication. Therefore, an efficient and facile strategy for convenient tuning of VSG morphologies and structures, particularly at significantly reduced temperatures, is of vital importance for practical applications at lowered cost. To date, impressive improvements have been made to reduce fabrication temperature and realize an efficient control of structure and morphology of VSG via sputtering, [28] thermal chemical vapor deposition (TCVD), [23] and plasma enhanced chemical vapor deposition (PECVD). [16] Compared with other techniques, PECVD offers the advantages of low substrate temperature, fast growth, substrate independence and good feasibility in controlling morphologies and structures. [18] In a typical PECVD system, the nonequilibrium plasma dissociates the carbon related gaseous precursors to produce reactive radicals as the building blocks for VSG and the generated energetic electrons boost the reaction kinetics of the growth process at low substrate temperature. We note that the electric field from the plasma sheath perpendicular to the substrate affects the growth Vertically standing graphene (VSG) films have demonstrated various appealing functionalities on the basis of excellent electrical/thermal conductivity and electrochemical/catalytic properties, owing to their unique morphology, preferable orientation of the basal planes, and adequate defects as effective catalytic sites. Most fabrication processes for VSG suffer from the disadvantage of high processing temperature, difficulty in structural control, or poor scalability, which limits their many potential applications. Herein, a scalable high-flux plasma-enhanced chemical vapor deposition system is designed, with streamlined magnetic field to enable high and uniform ion densi...

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Plasma-electric field controlled growth of oriented graphene for energy storage applications

Cited by 25 publications

References 63 publications

Single-step growth of graphene and graphene-based nanostructures by plasma-enhanced chemical vapor deposition

Single-step growth of graphene and graphene-based nanostructures by plasma-enhanced chemical vapor deposition

Transfer-Free Graphene-Like Thin Films on GaN LED Epiwafers Grown by PECVD Using an Ultrathin Pt Catalyst for Transparent Electrode Applications

Heater‐Free and Substrate‐Independent Growth of Vertically Standing Graphene Using A High‐Flux Plasma‐Enhanced Chemical Vapor Deposition

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