2014/04/27 by D. Talukdar, Peerapong Yotprayoonsak, Talukdar, D. +9
Engineering · Materials Science · Physics and Astronomy · #Carbon Nanotubes in Composites #FOS: Physical sciences #Graphene research and applications #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Molecular Junctions and Nanostructures #cond-mat.mes-hall
paper · pdf · doi:10.48550/arxiv.1404.6730
arxiv created 2014/04/27 · openalex publication_date 2014/04/27 · arxiv updated 2014/04/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Understanding the nature of metal/1D-semiconductor contacts such as metal/carbon nanotubes is a fundamental scientific and technological challenge for realizing high performance transistors\citeFrancois,Franklin. A Schottky Barrier(SB) is usually formed at the interface of the 2D metal electrode with the 1D semiconducting carbon nanotube. As yet, experimental\citeAppenzeller,Chen, Heinze, Derycke and numerical \citeLeonard, Jimenez studies have generally failed\citeSvensson to come up with any functional relationship among the relevant variables affecting carrier transport across the SB owing to their unique geometries and complicated electrostatics. Here, we show that localized states called the metal induced gap states (MIGS)\citeTersoff,Leonard already present in the barrier determines the transistor drain characteristics. These states seem to have little or no influence near the ON-state of the transistor but starts to affect the drain characteristics strongly as the OFF-state is approached. The role of MIGS is characterized by tracking the dynamics of the onset bias, Vo of non-linear conduction in the drain characteristics with gate voltage Vg. We find that Vo varies with the zero-bias conductance Go(Vg) for a gate bias Vg as a power-law: Vo ∼ Go(Vg)x with an exponent x. The origin of this power-law relationship is tentatively suggested as a result of power-law variation of effective barrier height with Vg, corroborated by previous theoretical and experimental results\citeAppenzeller. The influence of MIGS states on transport is further verified independently by temperature dependent measurements. The unexpected scaling behavior seem to be very generic for metal/CNT contact providing an experimental forecast for designing state of the art CNT devices.