Formation of ripples in atomically thin MoS sub(2) and local strain engineering of electrostatic properties

Ripple is a common deformation in two-dimensional materials due to localized strain, which is expected to greatly influence the physical properties. The effects of the ripple deformation in the MoS sub(2) layer on their physics, however, are rarely addressed experimentally. We here grow atomically thin MoS sub(2) nanostructures by employing a vapor phase deposition method without any catalyst and observed the ripples in MoS sub(2) nanostructures. The MoS sub(2) ripples exhibit quasi-periodical ripple structures in the MoS sub(2) surface. The heights of the ripples vary from several angstroms to tens of nanometers and the wavelength is in the range of several hundred nanometers. The growth mechanism of rippled MoS sub(2) nanostructures is elucidated. We have also simultaneously investigated the electrostatic properties of MoS sub(2) ripples by using Kelvin probe force microscopy, which shows inhomogeneous surface potential and charge distributions for MoS sub(2) ripple nanostructures with different local strains.