The role of etching on growth of adlayer graphene by chemical vapor deposition

Guo, Zi Rui; Zu, Pengjiao; Liu, Ze; Muswelu, Cecillia; Cao, Yuhao; Li, Jun; Li, Jia

doi:10.1016/j.diamond.2021.108549

Cited by 2 publications

(3 citation statements)

References 35 publications

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“…This indicates that graphene may be preferentially etched where an adlayer exists underneath. Such a morphology might also be formed via adlayer formation through etch holes in a monolayer, as suggested in a recent work . The etch holes indicated by arrows in Figure e,f were formed by the former mechanism.…”

Section: Resultssupporting

confidence: 58%

“…Such a morphology might also be formed via adlayer formation through etch holes in a monolayer, as suggested in a recent work. 30 The etch holes indicated by arrows in Figure 3e,f were formed by the former mechanism. No adlayer was observed to have grown from the hole indicated by an arrow in Figure 3e, which excludes the latter mechanism, suggesting that the hole was formed by etching at the edge of the pre-existing adlayer.…”

Section: Resultsmentioning

confidence: 94%

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Graphene-Based Physically Unclonable Functions with Dual Source of Randomness

Lee

Pekdemir

Kayacı

et al. 2023

ACS Appl. Mater. Interfaces

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There is growing interest in systems with randomized responses for generating physically unclonable functions (PUFs) in anticounterfeiting and authentication applications. Atomic-level control over its thickness and unique Raman spectrum make graphene an attractive material for PUF applications. Herein, we report graphene PUFs that emerge from two independent stochastic processes. Randomized variations in the shape and number of graphene adlayers were achieved by exploiting and improving the mechanistic understanding of the chemical vapor deposition of graphene. The randomized positioning of the graphene domains was then facilitated by dewetting the polymer film, followed by oxygen plasma etching. This approach yielded surfaces with randomly positioned and shaped graphene islands with varied numbers of layers and, therefore, Raman spectra. Raman mapping of surfaces resulted in multicolor images with a high encoding capacity. Advanced feature-matching algorithms were employed for the authentication of multicolor images. The use of two independent stochastic processes on a two-dimensional nanomaterial platform enables the creation of unique and complex surfaces that excessively challenge clonability.

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Section: Resultssupporting

confidence: 58%

Section: Resultsmentioning

confidence: 94%

Graphene-Based Physically Unclonable Functions with Dual Source of Randomness

Lee

Pekdemir

Kayacı

et al. 2023

ACS Appl. Mater. Interfaces

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“…For the graphene domain shown in Figure m, we estimated the volume of the pit part and the graphene part based on the AFM morphology image and further calculated the number of carbon atoms corresponding to the volume to be 4.08 × 10 6 and 1.57 × 10 8 , respectively, which are almost on the same order of magnitude. Therefore, we inferred that carbon atoms sublimating from pit regions participate in the local formation of multilayer CVD-G domains …”

Section: Resultsmentioning

confidence: 99%

Suppression of Nucleation Density in Twisted Graphene Domains Grown on Graphene/SiC Template by Sequential Thermal Process

Yao,

Inoue,

Takamura

et al. 2024

Crystal Growth & Design

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We investigated the growth of twisted graphene on graphene/silicon carbide (SiC-G) templates by metal-free chemical vapor deposition (CVD) through a sequential thermal (ST) process, which exploits the ultraclean surface of SiC-G without exposing the surface to air before CVD. By conducting control experiments with SiC-G templates exposed to air (AirE process), structural analysis by atomic force microscopy revealed that the nucleation density of CVD-grown graphene (CVD-G) was significantly suppressed in the ST process under the same growth conditions. The nucleation behavior on SiC-G surfaces was observed to be very sensitive to the carbon source concentration and process temperature. Nucleation on the ultraclean surface of SiC-G prepared by the ST process requires a higher partial pressure of the carbon source compared to that on the surface of SiC-G prepared by the AirE process. Moreover, an analysis of CVD-G growth over a wide temperature range indicated that the nucleation phenomena change dramatically with a threshold temperature of 1300 °C, possibly due to arising etching effects. The successful synthesis of twisted few-layer graphene (tFLG) was affirmed by Raman spectroscopy, in which an analysis of the G′-band proved thre was a high ratio of twisted structure in CVD-G. These results demonstrate that metal-free CVD utilizing ultraclean templates is an effective approach for the scalable production of large-domain tFLG, which is valuable for electronic applications.

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The role of etching on growth of adlayer graphene by chemical vapor deposition

Cited by 2 publications

References 35 publications

Graphene-Based Physically Unclonable Functions with Dual Source of Randomness

Graphene-Based Physically Unclonable Functions with Dual Source of Randomness

Suppression of Nucleation Density in Twisted Graphene Domains Grown on Graphene/SiC Template by Sequential Thermal Process

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