The Role of Transport Agents in MoS₂ Single Crystals

Abstract

We report resistivity, thermoelectric power, and thermal conductivity of MoS 2 single crystals prepared by the chemical vapor transport (CVT) method using I 2, Br 2, and TeCl 4 as transport agents. The material presents low-lying donor and acceptor levels, which dominate the in-plane charge transport. Intercalates into the van der Waals gap strongly influence the interplane resistivity. Thermoelectric power displays the characteristics of strong electron–phonon interaction. A detailed theoretical model of thermal conductivity reveals the presence of a high number of defects in the MoS 2 structure. We show that these defects are inherent to CVT growth method, coming mostly from the transport agent molecules inclusion as identified by total reflection X-ray fluorescence analysis (TXRF) and in-beam activation analysis (IBAA).