Nonlinear bandgap opening behavior of BN co-doped graphene
2016 (English)In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 107, 857-864 p.Article in journal (Refereed) Published
We have demonstrated a nonlinear behavior for the bandgap opening of doped graphene by controlling the concentration of B and N co-dopants. X-ray absorption and emission spectra reveal that the bandgap increases from 0 to 0.6 eV as the concentration of BN dopants is increased from 0 to 6%, while the bandgap closes when the doping concentration becomes 56%. This nonlinear behavior of bandgap opening of the BN-doped graphene depending on the BN concentrations is consistent with the valenceband photoemission spectroscopic measurements. The spatially resolved B, N and C K-edge scanning transmission x-ray microscopy and their x-ray absorption near- edge structure spectra all support the scenario of the development of h-BN-like domains at high concentrations of BN. Ab initio calculation, by taking into account of the strong correlation between the bandgap and the geometry/concentration of the dopant, has been performed with various BN-dopant nano-domains embedded in the graphene monolayer to verify the unique bandgap behavior. Based on the experimental measurements and ab initio calculation, we propose the progressive formation of a phase-separated zigzag-edged BN domain from BN quantum dots with increasing BN-dopant concentration to explain the extraordinary nonlinear behavior of bandgap opening of BN-doped graphene sheets. This study reveals a new way to engineer the bandgap of low-dimensional systems.
Place, publisher, year, edition, pages
Elsevier, 2016. Vol. 107, 857-864 p.
Hexagonal Boron-Nitride, X-Ray Spectromicroscopy, Augmented-Wave Method, Electronic-Structures, Cluster-Analysis, Nitrogen, Gap, Growth, Photoluminescence, Spectroscopy
Other Chemistry Topics
IdentifiersURN: urn:nbn:se:kth:diva-192381DOI: 10.1016/j.carbon.2016.06.091ISI: 000380803600099ScopusID: 2-s2.0-84976648122OAI: oai:DiVA.org:kth-192381DiVA: diva2:968992
QC 201609132016-09-132016-09-122016-09-13Bibliographically approved