(Invited) Atomic-Scale Functionalization and Characterization of 2D Materials

Abstract

As 2D materials set their path into our next generation nanoelectronics, enriching their functionalities and complementing their limitations become more important. In particular, novel strategies for controllable incorporation of substitutional and intercalated atoms need to be developed. Here, we report on modifying 2D materials at the atomic-scale by ultra-low energy ion implantation to functionalize their properties and explore their limits. I will present our recent work on graphene on two topics: substitutional manganese (Mn) atoms for magnetic doping [1] and intercalation of noble gases to produce nanobubbles with small radii and high aspect ratios. On the one hand, we have characterized in detail the atomic structure of substitutional Mn and graphene’s Dirac-like band structure doped with up to 1% substitutional Mn. On the other hand, the structural inspection of our graphene nanobubbles has revealed a so far unexplored small-radius limit, associated with high aspect ratios as well as extreme pressure and strain. Our approach is based on a wide range of characterization techniques (structural and electronic), including scanning tunneling microscopy and spectroscopy (STM/STS), Raman spectroscopy, synchrotron-based X-ray photoelectron spectroscopy (XPS), angle-resolved photoemission spectroscopy (ARPES), X-ray magnetic circular dichroism (XMCD), among others. These experimental studies are complemented by density functional theory (DFT) and molecular dynamics (MD) simulations.[1] P. C. Lin et al., ACS nano 15(3), 5449-5458 (2021). Figure 1