All-Graphene Planar Double-Quantum-Dot Resonant Tunneling Diodes

• Published in: IEEE journal of the Electron Devices Society Vol. 4; no. 1; pp. 30 - 39
• Main Authors: Al-Dirini, Feras, Mohammed, Mahmood A., Hossain, Faruque M., Nirmalathas, Thas Ampalavanapillai, Skafidas, Efstratios
• Format: Journal Article
• Language: English
• Published: IEEE 01.01.2016
• Subjects: Fabrication; Graphene; Green's function methods; Nanoscale devices; NDR; Negative Differential Resistance; Planar; Quantum Dot; Quantum dots; Resonant Tunneling; Resonant tunneling devices; Tunable; tunable; planar; Graphene; negative differential resistance; quantum dot; resonant tunneling; NDR
• ISSN: 2168-6734; 2168-6734
• DOI: 10.1109/JEDS.2015.2490178

This paper proposes a new class of resonant tunneling diodes (RTDs) that are planar and realizable with a single graphene nanoribbon. Unlike conventional RTDs, which incorporate vertical quantum well regions, the proposed devices incorporate two confined planar quantum dots within the single graphene nanoribbon, giving rise to a pronounced negative differential resistance (NDR) effect. The proposed devices, termed here as planar double-quantum-dot RTDs, and their transport properties are investigated using quantum simulations based on nonequilibrium Green's function formalism and the extended Huckel method. The proposed devices exhibit a unique current-voltage waveform consisting of a single pronounced current peak with an extremely high, in the order of 10 4 , peak-to-valley ratio. The position of the current peak can be tuned between discrete voltage levels, allowing digitized tunability, which is exploited to realize multi-peak NDR devices.