Squeezed metallic droplet with tunable Kubo gap and charge injection in transition metal dichalcogenides

TL;DR

This paper demonstrates a 2D metallic transition metal dichalcogenide nanocluster with a tunable Kubo gap, exhibiting unique electronic properties and potential applications in sensors and reconfigurable devices.

Contribution

It introduces a novel 2D metallic nanodomain with a size-dependent Kubo gap, combining properties of 3D metallic droplets with 2D material characteristics.

Findings

Achieved Kubo gap in 2D MoTe2 nanoclusters.

Observed photon emission and ballistic charge injection.

Maintained bond integrity despite size reduction.

Abstract

Shrinking the size of a bulk metal into nanoscale leads to the discreteness of electronic energy levels, the so-called Kubo gap. Renormalization of the electronic properties with a tunable and size-dependent Kubo gap renders fascinating photon emission and electron tunneling. In contrast with usual three-dimensional (3D) metal clusters, here we demonstrate that Kubo gap can be achieved with a two-dimensional (2D) metallic transition metal dichalcogenide (i.e., 1T'-phase MoTe2) nanocluster embedded in a semiconducting polymorph (i.e., 1H-phase MoTe2). Such a 1T'-1H MoTe2 nanodomain resembles a 3D metallic droplet squeezed in a 2D space which shows a strong polarization catastrophe while simultaneously maintains its bond integrity which is absent in traditional delta-gapped 3D clusters. The weak screening of the host 2D MoTe2 leads to photon emission of such pseudo-metallic systems and a ballistic injection of carriers in the 1T'-1H-1T' homojunctions which may find applications in sensors and 2D reconfigurable devices.