Suppressed Thermal Conductivity in van der Waals Semiconductor SnS ₂ by Stacking Engineering

Thermal transport in crystals highly depends on the vibrations of the lattice. If the intrinsic period of the lattice is disrupted, phonon transport within the lattice will be suppressed. Herein, a strategy is reported for thermal conductivity suppression in the 2D van der Waals semiconductor SnS 2 by layer period engineering. The stacking period for SnS 2 layers is broken by mechanical alloying combined with spark plasma sintering. Double Cs‐corrected transmission electron microscopy reveals that 2H and 4H SnS 2 structures coexist by stacking along the c ‐axis, demonstrating the long‐range ordered but short‐range disordered arrangement. As a result, the lattice thermal conductivity of SnS 2 decreases from ≈2.0 to ≈1.18 W m −1 K −1 at 673 K. The strategy promises the potential application of SnS 2 in scenarios where low thermal conductivity is essential such as thermoelectric materials.