Edge contact between Graphene & h-BN encapsulated single walled carbon nanotubes and their electrical properties

Abstract

Carbon nanotube is promising materials at electronics because of its excellent electrical property which origins from ballistic transport. However its electrical property is lower than theoretic range because of contact resistance between channel and electrode. It is necessary to research and reduce contact resistance to sustain their nature properties. Also importance of contact resistance increases as scales go down. In this research, we approached two method to lower contact resistance. First, using graphene electrode instead of metal. Graphene is known as excellent electrical conductivity. Also graphene is graphitic allotropes with carbon nanotubes, so it has potential to make better combination with carbon nanotubes than metal electrode. Second approach is geometry conversion from top contact to edge contact. Different with top contact which forms van der Waals gap at contact region, edge contact forms chemical contact at edge. This will give potential to lower contact resistance. Combining these two strategies, we demonstrated edge contact device with carbons. Also to increase performance of devices, we deposited gold pad to make extra electrical path and increase conductivity. As a result, graphene interlayer device showed better performance than edge contact with gold only because carbons made shorter chemical bindings at edge and gold supported overall conductivity. Lastly, edge contact showed potential in integration which has constant contact resistances regardless of their scales compare to top contact devices which depends on contact region.