  The weak van der Waals interlayer interactions in the transition metal
dichalcogenide (TMD) materials have created a rich platform to study their
exotic electronic properties through chemical doping or physical gating
techniques. We reported bulk superconductivity up to 7.6 K through careful
manipulation of the charge carrier density and interlayer spacing d in the
chemically intercalated two dimensional 1T-SnSe2 phase. We found, for the first
time in the two dimensional SnSe2, that polar organic molecules cointercalated
with the alkali metal Li into the basal layers, thus significantly enhancing
the superconducting Tc. We observed that the Tc scales with the basal spacing
distance, meanwhile being almost independent of x in Lix(THF)ySnSe2 system. Our
results offers a new general chemical route to study the rich electron
correlations and the interplay of charge density wave and unconventional
superconductivity in the two dimensional material.

Superconductivity