We report here the current–voltage (i–V) characteristics of several (n++- Si /MNOPE/ C 60/ Pt -tip) or (n++- Si /MNOPE/SWCNT/ Pt -tip) junctions, where MNOPE = 2'-mononitro-4, 4'-bis(phenylethynyl)-1-phenylenediazonium and SWCNT = single wall carbon nanotube. A layer of C 60 or SWCNT-derivatized MNOPE has strong effect on the i–V behavior of the junctions, including rectification, negative differential resistance (NDR) and switching behaviors. The i–V curve of a grafted molecular monolayer (GMM) of MNOPE atop n++- Si shows NDR behavior, whereas those of C 60- and SWCNT-derivatized GMMs of MNOPE on n++- Si show strong rectifying behavior with opposite rectification polarities. With C 60, larger currents were found with negative tip bias, while with SWCNT, the forward top bias was positive. Because C 60 tends to be a good electron acceptor and SWCNTs tend to be good electron donors, they show different i–V behavior, as observed. Some of the (n++- Si /MNOPE/SWCNT/ Pt -tip) junctions also show reversible bistable switching behavior.
Achieved negative differential resistance behavior of Si/B-substituted into a C6 chain sandwiched between capped carbon nanotube junctions
