Designing topological defects in 2D materials using scanning probe microscopy and a self-healing mechanism: a density functional-based molecular dynamics study

Abstract

Engineering of materials at the atomic level is one of the most important aims of nanotechnology. The unprecedented ability of scanning probe microscopy to address individual atoms opened up the possibilities for nanomanipulation and nanolitography of surfaces and later on of two-dimensional materials. While the state-of-the-art scanning probe lithographic methods include, primarily, adsorption, desorption and repositioning of adatoms and molecules on substrates or tailoring nanoribbons by etching of trenches, the precise modification of the intrinsic atomic structure of materials is yet to be advanced. Here we introduce a new concept, scanning probe microscopy with a rotating tip, for engineering of the atomic structure of membranes based on two-dimensional materials. In order to indicate the viability of the concept, we present our theoretical research, which includes atomistic modeling, molecular dynamics simulations, Fourier analysis and electronic transport calculations. While stretching can be employed for fabrication of atomic chains only, our comprehensive molecular dynamics simulations indicate that nanomanipulation by scanning probe microscopy with a rotating tip is capable of assembling a wide range of topological defects in two-dimensional materials in a rather controllable and reproducible manner. We analyze two possibilities. In the first case the probe tip is retracted from the membrane while in the second case the tip is released beneath the membrane allowing graphene to freely relax and self-heal the pore made by the tip. The former approach with the tip rotation can be achieved experimentally by rotation of the sample, which is equivalent to rotation of the tip, whereas irradiation of the membrane by nanoclusters can be utilized for the latter approach. The latter one has the potential to yield a yet richer diversity of topological defects on account of a lesser determinacy. If successfully realized experimentally the concept proposed here could be an important step toward controllable nanostructuring of two-dimensional materials.

Reducing sheet resistance of self-assembled transparent graphene films by defect patching and doping with UV/ozone treatment

“…Spin polarization was included in calculations. This method has a proven record of various applications to graphene and graphene nanoribbons [27][28][29][30]. Transport properties are calculated by DFTB augmented with the Green's functions formalism [31].…”

Nanopatterning on calixarene thin films via low-energy field-emission scanning probe lithography

“…This multifunctional character makes it attractive for applications in ultrahigh-density data storage [2] and benchtop fabrication, where the patterning and imaging could be simultaneously achieved in a single-step process. A variety of methods based on SPM have been developed, such as mechanical force [3], thermal desorption [4], thermochemical modification [5], dip-pen nanolithography [6], and nanografting [7]. Among these nanopatterning methods based on SPM, some were commercialized in recently years, including thermomechanical modification (SwissLitho) and dip-pen nanolithography (Nanonics).…”