Thermal and electronic properties of exfoliated metal chalcogenides

Abstract

The thermal conductivity of layered metal chalcogenides such as MT 2 (M = Mo, W; T = S, Se) shows a marked decrease after exfoliation and subsequent restacking process. Random stacking of two-dimensional crystalline sheets circumvents thermal conduction pathways along a longitudinal direction, which results in a reduction in thermal conductivity. WS2 and WSe2 compounds retain p-type conducting behavior after exfoliation and restacking with decreased electrical conductivity due to the change in carrier concentration. MoSe2 compound exhibits metallic behavior < 130 °C with a small Seebeck coefficient, which results from metastable 1T-MoSe2 structure of the restacked phase.