Spacing dependent and cation doping independent superconductivity in intercalated 1T 2D SnSe ₂

Abstract

Abstract 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 basal spacing d in the chemically intercalated 2D 1T-SnSe 2 phase. We found, for the first time in the 2D SnSe 2 , that polar organic molecules cointercalated with the alkali metal Li into the basal layers, thus significantly enhancing the superconducting T c . We observed that the T c scales with the basal spacing distance, meanwhile being almost independent of x in Li x (THF) y SnSe 2 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 2D material.