A metastable trigonal phase, existing only as small patches on a chemically exfoliated few-layered, thermodynamically stable $1H$ phase of $\mathrm{Mo}{\mathrm{S}}_2$, is believed to critically influence the properties of $\mathrm{Mo}{\mathrm{S}}_2$-based devices. The electronic structure of this metastable phase is little understood in the absence of a direct experimental investigation of its electronic properties, complicated further by conflicting claims from theoretical investigations. We address this issue by investigating the electronic structure of this minority phase in chemically exfoliated $\mathrm{Mo}{\mathrm{S}}_2$ few-layered systems by enhancing its contributions with the use of highly spatially resolved ($\le 120$ nm resolution) photoemission spectroscopy and Raman spectroscopy in conjunction with state-of-the-art electronic structure calculations. Based on these results, we establish that the ground state of this phase, arrived at by the chemical exfoliation of $\mathrm{Mo}{\mathrm{S}}_2$ using the usual Li intercalation technique, is a small gap ($\sim 90\pm 40\mathrm{meV}$) semiconductor in contrast to most claims in the literature; we also identify the specific trigonal structure it has among many suggested ones.

• Received 27 July 2017
• Revised 19 October 2017

DOI:https://doi.org/10.1103/PhysRevB.96.195426