Thickness-Dependent In-Plane Thermoelectric Properties of PtTe2 with n-Type Conduction

Abstract

Two-dimensional (2D) transition-metal dichalcogenide-based homo- and heterostructures result in an unusual route to drastically increase the Seebeck coefficient through the interface-induced Seebeck effect. This current issue has motivated us to study the in-plane Seebeck coefficient and electrical conductivity of thickness-controlled 2D platinum ditelluride (PtTe2) thin films. The 2D PtTe2 thin films, synthesized by a simple tellurization process, exhibit a distinct morphological transition from holey to continuous thin films, depending on the pre-deposited Pt thicknesses. We observe higher in-plane Seebeck coefficient and power factor of ≥−6.8 μV/K and ≥6.11 μW/mK2, respectively, in the thicker 2D PtTe2 (≥20 nm) films, which is related to the more semimetallic transition with increasing PtTe2 film thickness. These studies for in-plane thermoelectric (TE) properties of the thickness-modulated 2D PtTe2 thin films offer potential feasibility for fabricating 2D-based TE devices comprising vertically stacked 2D/2D heterostructures.