Electrical Contacts and Conductivity of MoS2 Layer Structures

Abstract

The difficulty of making electrical contact to, and obtaining meaningful data from, strongly anisotropic layer structures is discussed and clarified for MoS2. An analysis of this anisotropy is presented and used to explain experimental results obtained from natural crystals of molybdenite.It is shown that annealed contacts on MoS2 make good electrical contact to the crystal by diffusing the contacting material parallel to the c axis and hence making contact to all of the layers. Just below room temperatures, activation energies [Formula: see text] parallel and [Formula: see text] perpendicular to the c axis are 0.04 to 0.08 eV but [Formula: see text] increases to between 0.08 and 0.12 eV below approximately 200 K, with [Formula: see text] at the low temperatures between 2 and 1.5 from sample to sample.The analysis is used to show that the published data for thick and thin crystals of MoTe2 can be made self-consistent.