Efficient Nitrogen Doping of Single-Layer Graphene Accompanied by Negligible Defect Generation for Integration into Hybrid Semiconductor Heterostructures

Abstract

While doping enables application-specific tailoring of graphene properties, it can also produce high defect densities that degrade the beneficial features. In this work, we report efficient nitrogen doping of ∼11 atom % without virtually inducing new structural defects in the initial, large-area, low defect, and transferred single-layer graphene. To shed light on this remarkable high-doping-low-disorder relationship, a unique experimental strategy consisting of analyzing the changes in doping, strain, and defect density after each important step during the doping procedure was employed. Complementary micro-Raman mapping, X-ray photoelectron spectroscopy, and optical microscopy revealed that effective cleaning of the graphene surface assists efficient nitrogen incorporation accompanied by mild compressive strain resulting in negligible defect formation in the doped graphene lattice. These original results are achieved by separating the growth of graphene from its doping. Moreover, the high doping level occurred simultaneously with the epitaxial growth of n-GaN micro- and nanorods on top of graphene, leading to the flow of higher currents through the graphene/n-GaN rod interface. Our approach can be extended toward integrating graphene into other technologically relevant hybrid semiconductor heterostructures and obtaining an ohmic contact at their interfaces by adjusting the doping level in graphene.

The influence of AlN buffer layer on the growth of self-assembled GaN nanocolumns on graphene

“…The dashed lines indicate D, G and 2D peak positions of pristine graphene. (2020) 10:853 | https://doi.org/10.1038/s41598-019-55424-z www.nature.com/scientificreports www.nature.com/scientificreports/ a compressive strain and/or a modification of the carbon atoms in the graphene network by the incorporation of nitrogen atoms which could lead to an n-type doping 57 . Such blue-shifting peaks have been observed when an intentional plasma nitridation of graphene using either nitrogen 58 or ammonia 59 causes the introduction of defects as well as changes in the chemical and electronic properties of graphene.…”

Epitaxy of Single‐Crystalline GaN Film on CMOS‐Compatible Si(100) Substrate Buffered by Graphene

“…The peaks at 398.7 and 399.6 eV come from the nitrogen‐doped graphene and do not correlate with the underneath layer (see Figure S7a, Supporting Information). The peak at 398.7 eV is assigned to pyridine‐like N, corresponding to the sp 2 CN bonding configuration, while the peak at 399.6 eV indicates the presence of pyrroline‐like N corresponding to sp 3 CN . After the NH 3 pretreatment of graphene, both sp 2 CN and sp 3 CN are formed, as shown schematically in Figure c.…”

Growth of boron-doped few-layer graphene by molecular beam epitaxy

“…In both cases, a blue shift is observed, which can be attributed mainly to the boron doping effect in graphene as the p-type. 8,25 G peak shifts of up to 8 and 10 cm À1 are observed for the films prepared using approaches 1 and 2 under the highest B flux, respectively. For the 2D peak, the corresponding values are 6.5 and 7.5 cm À1 , respectively.…”

“…Previous works have shown that the introduction of nitrogen dopants can open a bandgap in graphene 6,7 and also increase its carrier concentration. 8 Nitrogen and boron can induce ntype and p-type doping in graphene, respectively, but unintentional p-type doping can occur in pristine graphene due to species absorbed from the atmosphere such as oxygen and water vapor. 9 Since uncontrolled p-type doping is easily achieved in graphene, a higher research effort was devoted to nitrogen-doping in order to produce n-type graphene.…”