Electron and thermal transport via Variable Range Hopping in MoSe$_{2}$ single crystals

TL;DR

This study investigates the electronic and thermal transport properties of MoSe₂ single crystals, revealing variable range hopping as the dominant conduction mechanism at certain temperatures and highlighting strong anisotropy and localization effects.

Contribution

It provides detailed resistivity and Seebeck coefficient measurements, demonstrating VRH behavior and structural anisotropy in MoSe₂ single crystals for the first time.

Findings

VRH model explains transport above 31 K

Strong structural anisotropy indicated by resistivity

High localization degree inferred from VRH fittings

Abstract

Bulk single crystal Molybdenum diselenide has been studied for its electronic and thermal transport properties. We perform resistivity measurements with current in-plane (CIP) and current perpendicular to plane (CPP) as a function of temperature. The CIP measurements exhibit metal to semiconductor transition at $\simeq 31$ K. In the semiconducting phase ($T > 31$ K), the transport is best explained by variable range hopping (VRH) model. Large magnitude of resistivity in CPP mode indicates strong structural anisotropy. Seebeck coefficient as a function of temperature measured in the range $90 - 300$ K, also agrees well with the VRH model. The room temperature Seebeck coefficient is found to be $139$ $\mu$V/K. VRH fittings of the resistivity and Seebeck coefficient data indicate high degree of localization.