(Invited) Processing of 2D Materials Using Ion Implantation

Abstract

Functionalization of 2D materials generally requires the modification of their physicochemical properties. Several approaches have been explored: the use of different substrates, creation of intrinsic defects (e.g. vacancies), adsorption and intercalation (of atoms, clusters or molecules), substitutional doping, among others. For incorporation of substitutional or intercalated elements, despite the numerous approaches that have been investigated, a major challenge remains: the limited control over the concentration and form of incorporation. An alternative approach is to incorporate the foreign species by ultra-low energy (ULE) ion implantation, precisely tuning the number of implanted ions and their kinetic energy. Here, I review our recent work on ULE ion implantation of 2D materials, with emphasis on substitutional doping and intercalation of graphene. Our approach is based on a wide range of characterization techniques (structural and electronic), including scanning tunneling microscopy and spectroscopy (STM/STS), synchrotron-based X-ray photoelectron spectroscopy (XPS), angle-resolved photoemission spectroscopy (ARPES), X-ray magnetic circular dichroism (XMCD), transport measurements, among others. These experimental studies are complemented by density functional theory (DFT) and molecular dynamics (MD) simulations.