Periodic Nanoarray of Graphene pn‐Junctions on Silicon Carbide Obtained by Hydrogen Intercalation. (27th January 2022)

• Record Type: Journal Article
• Authors: Karakachian, Hrag; Rosenzweig, Philipp; Nguyen, T. T. Nhung; Matta, Bharti; Zakharov, Alexei A.; Yakimova, Rositsa; Balasubramanian, Thiagarajan; Mamiyev, Zamin; Tegenkamp, Christoph; Polley, Craig M.; Starke, Ulrich
• Is Part Of: Advanced functional materials. Volume 32:Number 18(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-01-27
• Subjects: 6H‐SiC mesa structures -- armchair graphene nanoribbon -- intercalation -- pn‐junction -- quasi‐free monolayer graphene; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202109839
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Graphene pn‐junctions offer a rich portfolio of intriguing physical phenomena. They stand as the potential building blocks for a broad spectrum of future technologies, ranging from electronic lenses analogous to metamaterials in optics, to high‐performance photodetectors important for a variety of optoelectronic applications. The production of graphene pn‐junctions and their precise structuring at the nanoscale remains to be a challenge. In this work, a scalable method for fabricating periodic nanoarrays of graphene pn‐junctions on a technologically viable semiconducting SiC substrate is introduced. Via H‐intercalation, 1D confined armchair graphene nanoribbons are transformed into a single 2D graphene sheet rolling over 6H‐SiC mesa structures. Due to the different surface terminations of the basal and vicinal SiC planes constituting the mesa structures, different types of charge carriers are locally induced into the graphene layer. Using angle‐resolved photoelectron spectroscopy, the electronic band structure of the two graphene regions are selectively measured, finding two symmetrically doped phases with p‐type being located on the basal planes and n‐type on the facets. The results demonstrate that through a careful structuring of the substrate, combined with H‐intercalation, integrated networks of graphene pn‐junctions could be engineered at the nanoscale, paving the way for the realization of novel optoelectronic device concepts. Abstract : A novel approach is introduced for the production of integrated networks of graphene pn‐junctions at the nanoscale. Via hydrogen intercalation, one‐dimensionally confined graphene nanoribbons are transformed into a single 2D graphene layer rolling over 6H‐SiC mesa structures. Due to the different surface terminations of the vicinal and basal SiC planes, different carrier types are induced into graphene, leading to an array of spatially well‐defined pn‐junctions.