Influence of Copper Morphology in Forming Nucleation Seeds for Graphene Growth

Abstract

We report that highly crystalline graphene can be obtained from well-controlled surface morphology of the copper substrate. Flat copper surface was prepared by using a chemical mechanical polishing method. At early growth stage, the density of graphene nucleation seeds from polished Cu film was much lower and the domain sizes of graphene flakes were larger than those from unpolished Cu film. At later growth stage, these domains were stitched together to form monolayer graphene, where the orientation of each domain crystal was unexpectedly not much different from each other. We also found that grain boundaries and intentionally formed scratched area play an important role for nucleation seeds. Although the best monolayer graphene was grown from polished Cu with a low sheet resistance of 260 Ω/sq, a small portion of multilayers were also formed near the impurity particles or locally protruded parts.

The Way towards Ultrafast Growth of Single‐Crystal Graphene on Copper

“…Besides, the impurities or step bunches can distort the growth trajectory and thus lower the growth rate. In addition, the inhomogeneities influence the growth rate slightly by affecting the diffusion process 53, 54, 55, 56, 57. Proper surface treatment technique, like long‐time annealing,65 polishing,56, 68, 87 melting and resolidification,72, 73, 74 and the above mentioned special Cu stacking configuration can accelerate the graphene growth by minimizing surface roughness.…”

“…The growth of large‐area high‐quality graphene films is fundamental for the upcoming graphene applications. Chemical vapour deposition (CVD) method offers good prospects to produce large‐size graphene films due to its simplicity, controllability and cost‐efficiency 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75. Many researches have verified that graphene can be catalytically grown on metallic substrates, like ruthenium (Ru),13, 14 iridium (Ir),15, 16 platinum (Pt),17, 18, …”

Charge and Spin Transport in Disordered Graphene-Based Materials

“…[18,26,181,120,25] Therefore, a great deal of effort has been made to eliminate the formation of GGBs during CVD by growing monocrystalline graphene. [182,183,184,185,186,187] There are two primary methods to obtain monocrystalline graphene with CVD. One method is to control the number of nucleation seeds (and thus the individual grain size) by polishing the copper substrate, [187] annealing it at high temperature before growth, [182,183] or using copper oxide.…”

“…[182,183,184,185,186,187] There are two primary methods to obtain monocrystalline graphene with CVD. One method is to control the number of nucleation seeds (and thus the individual grain size) by polishing the copper substrate, [187] annealing it at high temperature before growth, [182,183] or using copper oxide. [184,185] Recently, this approach has been able to realize CVD growth of individual grains on the order of several millimeters in diameter.…”

Flexible Supercapacitors – Development of Bendable Carbon Architectures

“…[55] Its unique structure and properties make graphene promising for a EDLC electrodes. [56] Although pure graphene sheets with high quality can be prepared by mechanical cleavage of graphite [57] or CVD method at high temperature, [58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73][74][75][76] these methods suffer from high cost, high temperature, substrate limitation, and extremely low yield. In addition, the surface of pristine graphene is so hydrophobic that pristine graphene tend to agglomerate in solvents, leading to the loss of excellent properties of monolayer graphene sheets.…”