Polytype control of MoS 2 using chemical bath deposition

Abstract

Molybdenum disulfide (MoS 2 ) has a wide range of applications from electronics to catalysis. While the properties of single-layer and multilayer MoS 2 films are well understood, controlling the deposited MoS 2 polytype remains a significant challenge. In this work, we employ chemical bath deposition, an aqueous deposition technique, to deposit large area MoS 2 thin films at room temperature. Using Raman spectroscopy and x-ray photoelectron spectroscopy, we show that the deposited MoS 2 polytype can be changed from semiconducting 2H MoS 2 on hydrophobic -CH 3 and -CO 2 C 6 F 5 terminated self-assembled monolayers (SAMs) to semimetallic 1T MoS 2 on hydrophilic -OH and -COOH terminated SAMs. The data suggest that the deposition of MoS 2 polytypes is controlled by the substrate surface energy. High surface energy substrates stabilize 1T MoS 2 films, while 2H MoS 2 is deposited on lower surface energy substrates. This effect appears to be general enabling the deposition of different MoS 2 polytypes on a wide range of substrates.