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Repeated growth and bubbling transfer of graphene with millimetre-size single-crystal grains using platinum.

Gao L, Ren W, Xu H, Jin L, Wang Z, Ma T, Ma LP, Zhang Z, Fu Q, Peng LM, Bao X, Cheng HM - Nat Commun (2012)

Bottom Line: The Pt substrates can be repeatedly used for graphene growth.The graphene shows high crystal quality with the reported lowest wrinkle height of 0.8 nm and a carrier mobility of greater than 7,100 cm(2) V(-1) s(-1) under ambient conditions.The repeatable growth of graphene with large single-crystal grains on Pt and its nondestructive transfer may enable various applications.

View Article: PubMed Central - PubMed

Affiliation: Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, China.

ABSTRACT
Large single-crystal graphene is highly desired and important for the applications of graphene in electronics, as grain boundaries between graphene grains markedly degrade its quality and properties. Here we report the growth of millimetre-sized hexagonal single-crystal graphene and graphene films joined from such grains on Pt by ambient-pressure chemical vapour deposition. We report a bubbling method to transfer these single graphene grains and graphene films to arbitrary substrate, which is nondestructive not only to graphene, but also to the Pt substrates. The Pt substrates can be repeatedly used for graphene growth. The graphene shows high crystal quality with the reported lowest wrinkle height of 0.8 nm and a carrier mobility of greater than 7,100 cm(2) V(-1) s(-1) under ambient conditions. The repeatable growth of graphene with large single-crystal grains on Pt and its nondestructive transfer may enable various applications.

No MeSH data available.


Coalescence of graphene grains.Scanning electron microscope (SEM) image of the coalescence of different graphene grains: (a) two; (b) three; (c) many; (d) continuous graphene film formed from grains. The graphene film completely covers the Pt substrates without any gaps. (e) Optical image of two coalesced graphene grains. (f) Raman mapping of the intensity of D band (1,300–1,400 cm−1) at the joint area of the two coalesced grains indicated by a red box in (e). The strong intensities along the line in the mapping indicate a grain boundary. The scale bars in (a–d) are 400 μm, in (e) 50 μm, and in (f) 20 μm.
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f2: Coalescence of graphene grains.Scanning electron microscope (SEM) image of the coalescence of different graphene grains: (a) two; (b) three; (c) many; (d) continuous graphene film formed from grains. The graphene film completely covers the Pt substrates without any gaps. (e) Optical image of two coalesced graphene grains. (f) Raman mapping of the intensity of D band (1,300–1,400 cm−1) at the joint area of the two coalesced grains indicated by a red box in (e). The strong intensities along the line in the mapping indicate a grain boundary. The scale bars in (a–d) are 400 μm, in (e) 50 μm, and in (f) 20 μm.

Mentions: It is first important to note that the predominant hexagonal graphene grains grown on Pt substrates have no reflex angle at the edges and no visible lines in their planes even in high-resolution scanning electron microscope images. Second, the size of the graphene grains is inversely proportional to the nucleation density of graphene. The nucleation density of graphene grains on Pt at a low CH4 concentration is very low, with a spacing of more than 1 mm, which provides space for the growth of large graphene grains. Third, with increasing growth time, no new nuclei are observed and only the continuous growth of graphene grains is observed. The lateral size of the graphene grains is roughly proportional to the growth time, with a mean growth rate of ~4 μm min−1 under the present growth conditions, which is about four times faster than that (~1 μm min−1) of the growth of hexagonal graphene grains on Cu. All the above facts indicate that the hexagonal grains with obtuse angles grown on Pt substrates should be single-crystal graphene grains, which are similar to the hexagonal single-crystal graphene grains grown on Cu foils by AP-CVD22, but have a much larger size up to more than a millimetre. It is worth noting that, by further increasing the growth time, large graphene grains join together and eventually form a continuous graphene film with grain boundaries, shown in Fig. 2.


Repeated growth and bubbling transfer of graphene with millimetre-size single-crystal grains using platinum.

Gao L, Ren W, Xu H, Jin L, Wang Z, Ma T, Ma LP, Zhang Z, Fu Q, Peng LM, Bao X, Cheng HM - Nat Commun (2012)

Coalescence of graphene grains.Scanning electron microscope (SEM) image of the coalescence of different graphene grains: (a) two; (b) three; (c) many; (d) continuous graphene film formed from grains. The graphene film completely covers the Pt substrates without any gaps. (e) Optical image of two coalesced graphene grains. (f) Raman mapping of the intensity of D band (1,300–1,400 cm−1) at the joint area of the two coalesced grains indicated by a red box in (e). The strong intensities along the line in the mapping indicate a grain boundary. The scale bars in (a–d) are 400 μm, in (e) 50 μm, and in (f) 20 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3293422&req=5

f2: Coalescence of graphene grains.Scanning electron microscope (SEM) image of the coalescence of different graphene grains: (a) two; (b) three; (c) many; (d) continuous graphene film formed from grains. The graphene film completely covers the Pt substrates without any gaps. (e) Optical image of two coalesced graphene grains. (f) Raman mapping of the intensity of D band (1,300–1,400 cm−1) at the joint area of the two coalesced grains indicated by a red box in (e). The strong intensities along the line in the mapping indicate a grain boundary. The scale bars in (a–d) are 400 μm, in (e) 50 μm, and in (f) 20 μm.
Mentions: It is first important to note that the predominant hexagonal graphene grains grown on Pt substrates have no reflex angle at the edges and no visible lines in their planes even in high-resolution scanning electron microscope images. Second, the size of the graphene grains is inversely proportional to the nucleation density of graphene. The nucleation density of graphene grains on Pt at a low CH4 concentration is very low, with a spacing of more than 1 mm, which provides space for the growth of large graphene grains. Third, with increasing growth time, no new nuclei are observed and only the continuous growth of graphene grains is observed. The lateral size of the graphene grains is roughly proportional to the growth time, with a mean growth rate of ~4 μm min−1 under the present growth conditions, which is about four times faster than that (~1 μm min−1) of the growth of hexagonal graphene grains on Cu. All the above facts indicate that the hexagonal grains with obtuse angles grown on Pt substrates should be single-crystal graphene grains, which are similar to the hexagonal single-crystal graphene grains grown on Cu foils by AP-CVD22, but have a much larger size up to more than a millimetre. It is worth noting that, by further increasing the growth time, large graphene grains join together and eventually form a continuous graphene film with grain boundaries, shown in Fig. 2.

Bottom Line: The Pt substrates can be repeatedly used for graphene growth.The graphene shows high crystal quality with the reported lowest wrinkle height of 0.8 nm and a carrier mobility of greater than 7,100 cm(2) V(-1) s(-1) under ambient conditions.The repeatable growth of graphene with large single-crystal grains on Pt and its nondestructive transfer may enable various applications.

View Article: PubMed Central - PubMed

Affiliation: Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, China.

ABSTRACT
Large single-crystal graphene is highly desired and important for the applications of graphene in electronics, as grain boundaries between graphene grains markedly degrade its quality and properties. Here we report the growth of millimetre-sized hexagonal single-crystal graphene and graphene films joined from such grains on Pt by ambient-pressure chemical vapour deposition. We report a bubbling method to transfer these single graphene grains and graphene films to arbitrary substrate, which is nondestructive not only to graphene, but also to the Pt substrates. The Pt substrates can be repeatedly used for graphene growth. The graphene shows high crystal quality with the reported lowest wrinkle height of 0.8 nm and a carrier mobility of greater than 7,100 cm(2) V(-1) s(-1) under ambient conditions. The repeatable growth of graphene with large single-crystal grains on Pt and its nondestructive transfer may enable various applications.

No MeSH data available.