1 research outputs found
Engineering the Structural and Electronic Phases of MoTe<sub>2</sub> through W Substitution
MoTe<sub>2</sub> is an exfoliable transition metal dichalcogenide (TMD) that crystallizes
in three symmetries: the semiconducting trigonal-prismatic 2H- or
α-phase, the semimetallic and monoclinic 1T<sup>′</sup>- or β-phase, and the semimetallic orthorhombic γ-structure.
The 2H-phase displays a band gap of ∼1 eV making it appealing
for flexible and transparent optoelectronics. The γ-phase is
predicted to possess unique topological properties that might lead
to topologically protected nondissipative transport channels. Recently,
it was argued that it is possible to locally induce phase-transformations
in TMDs, through chemical doping, local heating, or electric-field
to achieve ohmic contacts or to induce useful functionalities such as electronic phase-change memory elements. The combination of semiconducting and topological elements based upon the same compound might produce a new generation of high performance, low dissipation optoelectronic elements. Here, we show that it is possible to engineer the phases of MoTe<sub>2</sub> through W substitution by unveiling the phase-diagram of the Mo<sub>1–<i>x</i></sub>W<sub><i>x</i></sub>Te<sub>2</sub> solid solution, which displays a semiconducting to semimetallic transition as a function of <i>x</i>. We find that a small critical W concentration <i>x</i><sub>c</sub> ∼ 8% stabilizes the γ-phase at room temperature. This suggests that crystals with <i>x</i> close to <i>x</i><sub>c</sub> might be particularly susceptible to phase transformations induced by an external perturbation, for example, an electric field. Photoemission spectroscopy, indicates that the γ-phase possesses a Fermi surface akin to that of WTe<sub>2</sub>