Microscopy of hydrogen and hydrogen-vacancy defect structures on graphene devices

Abstract

We have used scanning tunneling microscopy (STM) to investigate two types of hydrogen defect structures on monolayer graphene supported by hexagonal boron nitride (h-BN) in a gated fieldeffect transistor configuration. The first H-defect type is created by bombarding graphene with 1-keV ionized hydrogen and is identified as two hydrogen atoms bonded to a graphene vacancy via comparison of experimental data to first-principles calculations. The second type of H defect is identified as dimerized hydrogen and is created by depositing atomic hydrogen having only thermal energy onto a graphene surface. Scanning tunneling spectroscopy (STS) measurements reveal that hydrogen dimers formed in this way open a new elastic channel in the tunneling conductance between an STM tip and graphene.

Electronic properties of chemically doped graphene

“…8d, where a spatial map for the value of λ at 20 mV is shown. Similar behavior has been recently reported for hydrogenated graphene [66].…”

Defect-induced magnetism and Yu-Shiba-Rusinov states in twisted bilayer graphene

“…3,10,11,35,36 First-principles calculations provide a powerful insight on effect of structural relaxation on the electronic structure of defective systems, together with the properties of the remaining unpaired electron. Chemisorption of a single H atom 23,24,[30][31][32] is a simple way of creating an imbalance between the number of A and B sites in graphene, with bare modification of the bipartite nature of graphene lattice [37][38][39][40][41][42][43][44][45][46][47] . The imbalance between the number of sites in the two sublattices has an important consequence that follows from Lieb's theorem 48 : a bipartite lattice with more A sites than B sites will show a number of zero modes proportional to such difference.…”

Atomic structures and interfacial engineering of ultrathin indium intercalated between graphene and a SiC substrate

“…Indeed, triangular defects in graphene have been well observed by STM images 53,54 which results from local charge transfer between the defect and the three adjacent carbon atoms in the graphene lattice. [55][56][57] These defects are attributed to be either monovacancies or foreign atoms substituted monovacancies in the graphene lattice. 55 Differential (dI/dV) spectroscopy is further used to elucidate the electronic signatures of the defects in 2D indium.…”