Intrinsic effects of substitution and intercalation on thermal transport in two-dimensional TiS$_2$ single crystals

TL;DR

This study investigates how substitution and intercalation doping affect thermal transport in TiS$_2$ single crystals, revealing significant reductions in thermal conductivity due to specific dopants, which is crucial for thermoelectric applications.

Contribution

It provides the first detailed analysis of intrinsic effects of various dopants on thermal transport in TiS$_2$ single crystals, isolating these effects from grain boundary scattering.

Findings

Ta doping reduces thermal conductivity five-fold.

Intercalation with excess Ti or Co impacts thermal transport.

Dopants significantly alter phonon scattering rates.

Abstract

The promising thermoelectric material TiS$_2$ can be easily chemically doped and intercalated. We present here studies of single crystals that are intercalated with excess Ti or Co, or substituted with Ta. We demonstrate the intrinsic impact of these dopants on the thermal transport in the absence of grain boundary scattering. We show that Ta doping has the greatest impact on the thermal scattering rate per ion added, leading to a five-fold reduction in the lattice thermal conductivity as compared to stoichiometric single crystals.