Low-Frequency Electronic Noise in Quasi-1D TaSe van der Waals Nanowires.

We report results of investigation of the low-frequency electronic excess noise in quasi-1D nanowires of TaSe capped with quasi-2D h-BN layers. Semimetallic TaSe is a quasi-1D van der Waals material with exceptionally high breakdown current density. It was found that TaSe nanowires have lower levels of the normalized noise spectral density, S/I, compared to carbon nanotubes and graphene (I is the current). The temperature-dependent measurements revealed that the low-frequency electronic 1/f noise becomes the 1/f type as temperature increases to ∼400 K, suggesting the onset of electromigration (f is the frequency). Using the Dutta-Horn random fluctuation model of the electronic noise in metals, we determined that the noise activation energy for quasi-1D TaSe nanowires is approximately E ≈ 1.0 eV. In the framework of the empirical noise model for metallic interconnects, the extracted activation energy, related to electromigration is E = 0.88 eV, consistent with that for Cu and Al interconnects. Our results shed light on the physical mechanism of low-frequency 1/f noise in quasi-1D van der Waals semimetals and suggest that such material systems have potential for ultimately downscaled local interconnect applications.