Kepaptsoglou, DemieHardcastle, Trevor P.Seabourne, Che R.Bangert, UrselZan, RecepAmani, Julian AlexanderRamasse, Quentin M.2019-08-012019-08-0120151936-08511936-086Xhttps://dx.doi.org/10.1021/acsnano.5b05305https://hdl.handle.net/11480/3853A combination of scanning transmission electron microscopy, electron energy loss spectroscopy, and ab initio calculations is used to describe the electronic structure modifications incurred by free-standing graphene through two types of single-atom doping. The N K and C K electron energy loss transitions show the presence of pi* bonding states, which are highly localized around the N dopant. In contrast, the B K transition of a single B dopant atom shows an unusual broad asymmetric peak which is the result of delocalized pi* states away from the B dopant. The asymmetry of the B K toward higher energies is attributed to highly localized sigma* antibonding states. These experimental observations are then interpreted as direct fingerprints of the expected p- and n-type behavior of graphene doped in this fashion, through careful comparison with density functional theory calculations.eninfo:eu-repo/semantics/openAccessgraphenedopingelectronic structureSTEMEELSab initio calculationsDFTArticle911113981140710.1021/acsnano.5b0530526446310WOS:000365464800090Q1