Atomic‐Scale Spectroscopic Imaging of the Extreme‐UV Optical Response of B‐ and N‐Doped Graphene

Abstract

Substitutional doping of graphene by impurity atoms such as boron and nitrogen, followed by atom‐by‐atom manipulation via scanning transmission electron microscopy, can allow for accurate tailoring of its electronic structure, plasmonic response, and even the creation of single atom devices. Beyond the identification of individual dopant atoms by means of “Z contrast” imaging, spectroscopic characterization is needed to understand the modifications induced in the electronic structure and plasmonic response. Here, atomic scale spectroscopic imaging in the extreme UV‐frequency band is demonstrated. Characteristic and energy‐loss‐dependent contrast changes centered on individual dopant atoms are highlighted. These effects are attributed to local dopant‐induced modifications of the electronic structure and are shown to be in excellent agreement with calculations of the associated densities of states.

Seed‐Initiated Synthesis and Tunable Doping Graphene for High‐Performance Photodetectors

“…In initial deposition stages of graphene, nucleation centers have compact sizes; at the same time as the deposition time increases, an excess of carbon atoms ultimately appear simultaneously to produce continuous films where nucleation centers serve as the chemically active sites, as illustrated in Figure i. The crystallography of the shape morphology and edge structure of the nucleation center for doped‐graphene epitaxial growth were studied . The spherical aberration‐corrected HR‐TEM allows for direct observation of atomic rearrangements, as shown in Figure j–m with a higher magnification (using the numbers I–IV to represent different edges corresponding to Figure h).…”

Pyrrolic, pyridinic, and graphitic sumanene as metal‐free catalyst for oxygen reduction reaction – A density functional theory study

“…The GRAP-SUMA shows a smaller pre-shift from Fermi level in the DOS plot than other N-doped SUMA. PDOS corresponding to N, C, and H also show a lesser peak shift for GRAP-SUMA [72,73]. Further, the Mulliken charge of the N atom in GRAP-SUMA is higher than other N-doped SUMA.…”

Probing the Dynamics of Topologically Protected Charged Ferroelectric Domain Walls with the Electron Beam at the Atomic Scale

“…Recently there has been a surge in interest of electron-beam-based atom-by-atom manipulation. [6][7][8][9] This presentation will focus on using the applied electric field (Ef) of the scanning transmission electron microscope (STEM) probe to move CDWs, and thus investigate their dynamics while imaging at the subatomic scale. As the applied Ef of an electron probe can be controlled in terms of dose, probe size, direction and speed a diverse set of experiments is possible without complicated sample preparation.…”