Open AccessDirect fabrication and characterization of vertically stacked Graphene/h-BN/Graphene tunnel junctions
Author(s) -
A.Z. AlZahrani,
Adel Alruqi,
Bhupendra Karki,
Milinda Kalutarakoralalage,
Jacek B. Jasiński,
Гамини Суманасекера
Publication year - 2021
Publication title -
nano express
Language(s) - English
Resource type - Journals
ISSN - 2632-959X
DOI - 10.1088/2632-959x/ac2e9e
Subject(s) - graphene , materials science , raman spectroscopy , graphene nanoribbons , chemical vapor deposition , quantum tunnelling , doping , x ray photoelectron spectroscopy , bilayer graphene , nanotechnology , fabrication , graphene oxide paper , optoelectronics , optics , chemical engineering , medicine , physics , engineering , alternative medicine , pathology
We have used a lithography free technique for the direct fabrication of vertically stacked two-dimensional (2D) material-based tunnel junctions and characterized by Raman, AFM, XPS. We fabricated Graphene/h-BN/Graphene devices by direct deposition of graphene (bottom layer), h-BN (insulating barrier) and graphene (top layer) sequentially using a plasma enhanced chemical vapor deposition on Si/SiO 2 substrates. The thickness of the h-BN insulating layer was varied by tuning the plasma power and the deposition time. Samples were characterized by Raman, AFM, and XPS. The I-V data follows the barrier thickness dependent quantum tunneling behavior for equally doped graphene layers. The resonant tunneling behavior was observed at room temperature for oppositely doped graphene layers where hydrazine and ammonia were used for n-doping of one of the graphene layers. The resonance with negative differential conductance occurs when the band structures of the two electrodes are aligned. The doping effect of the resonant peak is observed for varying doping levels. The results are explained according to the Bardeen tunneling model.