Electron transport properties of van der Waals heterostructures composed by one-dimensional carbon nanotubes and two-dimensional germanium selenide

Based on density functional theory (DFT) and non-equilibrium Green's function (NEGF) method, we studied the electron transport properties of van der Waals heterostructures (vdWHs) composed by (n,0) single-walled carbon nanotubes (SWCNTs) (n=5-11) and two-dimensional germanium selenide (2D GeSe). The (n,0)SWCNT/GeSe vdWHs (n=5-11) display distinct electron transport properties which can be tuned by the variation of diameter in SWCNTs. The results of the I-V characteristic curves show that the conductance of the (n,0)SWCNT/GeSe vdWHs (n=7-9,11) are improved after the integration of (n,0)SWCNT (n=7-9,11) with 2D GeSe. The current in (9,0)SWCNT/GeSe vdWH shows a quite high conductance, which can reach 100 μA under 1.5 V bias. The obtained transmission spectra under bias reveals the tendency of electrons and holes in participating the transport of (n,0)SWCNT/GeSe vdWHs (n=5-11).