Multiple intercalation stages and universal Tc enhancement through polar organic species in electron-doped 1T-SnSe2

TL;DR

This study demonstrates multiple intercalation stages and a universal enhancement of superconducting transition temperature (Tc) in electron-doped 1T-SnSe2 via cointercalation with lithium and organic molecules, revealing new ways to tune layered material properties.

Contribution

It introduces a method to achieve multiple intercalation stages and Tc enhancement in 1T-SnSe2 through cointercalation with Li and various organic molecules, expanding the control over electronic properties.

Findings

Multiple intercalation stages with distinct stacking patterns identified.

Superconducting Tc is universally increased with organic cointercalation.

Interlayer distance can be enlarged up to ~11 Å, affecting superconductivity.

Abstract

In this work, we report multiple intercalation stages and universal Tc enhancement of superconductivity in 1T-SnSe2 through Li and organic molecules cointercalation. We observe significantly increased lattice parameters up to 40 {\AA} and dramatically enlarged interlayer distance up to ~11{\AA} in Li and N,N-dimethylformamide (DMF) cointercalated SnSe2. Well-separated cointercalation stages with different stacking patterns have been discovered by carefully controlled reaction time and concentration of solutions. These cointercalation stages are superconductors showing different superconducting signals. In addition, Li and various organic species such as Acetone, Dimethyl sulfoxide (DMSO) and Tetrahydrofuran (THF) have been cointercalated into SnSe2 crystals, all of which show enhanced superconducting Tc compared to solely Li intercalated SnSe2. Our findings may provide more insight to effectively tune electronic structure of the lamellar structure through organic molecules co-regulation, and open a new strategy to engineer the physical properties of these layered materials by controlling their different intercalation stages.