Login / Signup

Growth of Ultraflat Graphene with Greatly Enhanced Mechanical Properties.

Bing DengYuan HouYing LiuTymofiy KhodkovStijin GoossensJilin TangYani WangRui YanYin DuFrank H L KoppensXiaoding WeiZhong ZhangZhongfan LiuHai-Lin Peng
Published in: Nano letters (2020)
Graphene grown on Cu by chemical vapor deposition is rough due to the surface roughening of Cu for releasing interfacial thermal stress and/or graphene bending energy. The roughness degrades the electrical conductance and mechanical strength of graphene. Here, by using vicinal Cu(111) and flat Cu(111) as model substrates, we investigated the critical role of original surface topography on the surface deformation of Cu covered by graphene. We demonstrated that terrace steps on vicinal Cu(111) dominate the formation of step bunches (SBs). Atomically flat graphene with roughness down to 0.2 nm was grown on flat Cu(111) films. When SB-induced ripples were avoided, as-grown ultraflat graphene maintained its flat feature after transfer. The ultraflat graphene exhibited extraordinary mechanical properties with Young's modulus ≈ 940 GPa and strength ≈ 117 GPa, comparable to mechanical exfoliated ones. Molecular dynamics simulation revealed the mechanism of softened elastic response and weakened strength of graphene with rippled structures.
Keyphrases
  • room temperature
  • carbon nanotubes
  • molecular dynamics simulations
  • walled carbon nanotubes
  • aqueous solution
  • machine learning
  • high resolution
  • oxidative stress
  • photodynamic therapy
  • single cell
  • high glucose