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Research Highlight

Negative Differential Resistance Devices From Atomically Precise Nanoscale Design

ORNL Image
Upper: Atomic structure of a paradigmatic 5-part GNR/intermediate heterostructure device, which consists of three intermediate segments separated by two GNR segments, with each segment having the length of four anthrylene units and graphene leads. Lower: Calculated I–V curve, exhibiting NDR from 0.38 to 0.55 V, marked with green shading.

Scientific Achievement

A new device structure consisting of multiple short graphene segments designed to produce negative differential resistance by alignment of electronic levels across the atomic interfaces.

Significance and Impact

This work demonstrates a feasible strategy to create a double barrier quantum dot structure at the atomic scale to deliver strong negative differential resistance (NDR), enabling nanoscale oscillators and signal amplifiers.

Research Details

– Density functional theory calculations  to determine electronic and molecular structure; Non-equilibrium Greens function approach provides transport properties.

– Scanning tunneling microscopy (STM) is used to write the designed structures in atomically precise graphene nanoribbons (GNRs) and validate the electronic properties.

Z. Xiao, C. Ma, J. Huang, L. Liang, W. Lu, K. Hong, B. G. Sumpter, A-P. Li, and J. Bernholc, "Design of atomically precise nanoscale negative differential resistance devices," Adv. Theory Simul. 1800172 (2018).  DOI: 10.1002/ adts.201800172;   C. Ma, Z. Xiao, J. Huang, L. Liang, W. Lu, K. Hong, B. G. Sumpter, J. Bernholc, and A-P. Li, "Direct writing of heterostructures in single atomically precise graphene nanoribbons," Phys. Rev. Mater. 3, 016001 (2019).  DOI: 10.1103/PhysRevMaterials.3.016001