Direct and Scalable Deposition of Atomically Thin Low-Noise MoS₂ Membranes on Apertures

Abstract

Molybdenum disulfide (MoS2) flakes can grow beyond the edge of an underlying substrate into a planar freestanding crystal. When the substrate edge is in the form of an aperture, reagent-limited nucleation followed by edge growth facilitate direct and selective growth of freestanding MoS2 membranes. We have found conditions under which MoS2 grows preferentially across micrometer-scale prefabricated solid-state apertures in silicon nitride membranes, resulting in sealed membranes that are one to a few atomic layers thick. We have investigated the structure and purity of our membranes by a combination of atomic-resolution transmission electron microscopy, elemental analysis, Raman spectroscopy, photoluminescence spectroscopy, and low-noise ion-current recordings through nanopores fabricated in such membranes. Finally, we demonstrate the utility of fabricated ultrathin nanopores in such membranes for single-stranded DNA translocation detection.

Booming Development of Group IV–VI Semiconductors: Fresh Blood of 2D Family

“…CVD‐grown graphene has made great breakthrough in the growth of large‐area graphene 17, 155, 156, 157, 158, 159, 160. Recently, the synthesis of 2DLMs via CVD methods has been illustrated in many reports especially for MoS 2 ,30, 31, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185 which also shows promising applications in electronics and optoelectronics. Up to now, there are several reports on synthesizing 2D GIVMCs nanoflakes via CVD method, which is still at the initial stage.…”

Interfacing solid‐state nanopores with gel media to slow DNA translocations

“…Ideally, a voltage could be applied that would overcome the issue of Brownian motion while simultaneously reducing the velocity to a level where each nucleotide on a ssDNA molecule would be sampled for ≥20 μs. Importantly, advances have been made in increasing the bandwidth of detection instruments to the 1 to 5 MHz range [27,28] which reduce the necessary dwell time of each individual nucleotide, however molecules are still translocating over an order of magnitude too quickly for complete nanopore-based DNA sequencing to become a reality [27]. In order to address this issue, researchers have turned their attention to three basic components of the nanopore system -the environment, the molecule of interest, and the nanopore itself.…”

Geometrical Effect in 2D Nanopores

“…RMS noise is ∼35 pA at 10k lowpass filtering, which is comparable to MoS 2 nanopores. 12,33 The major contribution is low frequency 1/f noise, 34 which can be reduced significantly by shrinking the region of suspended h-BN to a circular aperture with a diameter of 50 nm. In this way, we obtain a very good signal-to-noise ratio (SNR) which is up to 20.…”