Adhesion of a Single-Walled Carbon Nanotube on Hydrogen-Terminated Silicon(111) Surface: Molecular Mechanics Simulation Approach

The adhesion of the single-walled carbon nanotube (SWCNT) (10, 10) on the hydrogen-terminated silicon(111) surface [H-Si(111)] is investigated using full atomistic molecular mechanics simulation. By deforming a SWCNT with various bending angle, we found that the buckling is generated at ∼40°, As the bending angle is increased, the entailed strain energy is increased quadratically at  < 50° and thereafter increased linearly. Using the lying-down configuration of SWCNT with various lengths on the H-Si(111), we found that the binding of SWCNT becomes stronger as a function of the length of the CNT, and the increasing rate is −3.503 kcal/mol/Å. From analyzing the adhesion energy defined as a sum of the strain energy and the binding energy, we also found that a CNT should be sufficiently long to achieve stable adhesion on H-Si(111), indicating that a SWCNT (10, 10) with a buckling ( = 90°) needs to be longer than ∼675 Å assuming the buckling energy is ∼2440 kcal/mol. The adhesion energy is destabilized as the bending angle is increased for a given CNT length, indicating that the adhesion of CNT with 149.2 Å of length is merely sustain within a small deformation ( < ∼20°), which will be expanded with increasing the CNT length.