Polytype Control of MoS₂ Using Chemical Bath Deposition

Molybdenum disulfide (MoS₂) has a wide range of applications from electronics to catalysis. While the properties of single-layer and multilayer MoS₂ films are well understood, controlling the deposited MoS₂ polytype remains a significant challenge. In this work, we employ chemical bath deposition, an aqueous deposition technique, to deposit large area MoS₂ thin films at room temperature. Using Raman spectroscopy and x-ray photoelectron spectroscopy, we show that the deposited MoS₂ polytype can be changed from semiconducting 2H MoS₂ on hydrophobic -CH₃ and -CO₂C₆F₅ terminated self-assembled monolayers (SAMs) to semimetallic 1T MoS₂ on hydrophilic -OH and -COOH terminated SAMs. The data suggest that the deposition of MoS₂ polytypes is controlled by the substrate surface energy. High surface energy substrates stabilize 1T MoS₂ films, while 2H MoS₂ is deposited on lower surface energy substrates. This effect appears to be general enabling the deposition of different MoS₂ polytypes on a wide range of substrates. ©2019 Author(s).