  Two-dimensional (2D) transition-metal dichalcogenide (TMDs) MoTe2 has
attracted much attention due to its predicted Weyl semimetal (WSM) state and a
quantum spin Hall insulator in bulk and monolayer form, respectively. We find
that the superconductivity in MoTe2 single crystal can be much enhanced by the
partial substitution of the Te ions by the S ones. The maximum of the
superconducting temperature TC of MoTe1.8S0.2 single crystal is about 1.3 K.
Compared with the parent MoTe2 single crystal (TC=0.1 K), nearly 13-fold in TC
is improved in MoTe1.8S0.2 one. The superconductivity has been investigated by
the resistivity and magnetization measurements. MoTe2-xSx single crystals
belong to weak coupling superconductors and the improvement of the
superconductivity may be related to the enhanced electron-phonon coupling
induced by the S-ion substitution. A dome-shape superconducting phase diagram
is obtained in the S-doped MoTe2 single crystals. MoTe2-xSx materials may
provide a new platform for our understanding of superconductivity phenomena and
topological physics in TMDs.
