Highly conductive group VI transition metal dichalcogenide films by solution-processed deposition

Abstract

A new soluble synthetic route was developed to fabricate thin films of layered structure transition metal dichalcogendies, MoS2 and WS2. High-quality thin films of the dichalcogenides were prepared using new soluble precursors, (CH3NH3)2MS4 (M = Mo, W). The precursors were dissolved in organic solvents and spun onto substrates via both single- and multistep spin coating procedures. The thin films were formed by the thermal decomposition of the coatings under inert atmosphere. Structural, electrical, optical absorption, thermal, and transport properties of the thin films were characterized. Surface morphology of the films was analyzed by atomic force microscopy and scanning electron microscopy. Highly conductive and textured n-type MoS2 films were obtained. The measured room temperature conductivity ∼50 Ω−1 cm−1 is substantially higher than the previously reported values. The n-type WS2 films were prepared for the first time using solution-processed deposition. WS2 displays a conductivity of ∼6.7 Ω−1 cm−1 at room temperature.

Quantum spin Hall states in graphene interacting with WS2 or WSe2

“…18 The structural and electronic properties have been studied extensively, see Ref. 19 and the references therein, as WS 2 is widely utilized for n/pdoped field effect transistors, for example. 20 Experimentally, synthesis and characterization of graphene on WS 2 have been reported in Ref.…”

Solution Processing of Chalcogenide Semiconductors via Dimensional Reduction

“…A similar approach with (CH 3 NH 3 ) 2 MS 4 (M ¼ W, Mo) dissolved in organic solvents and using an inert atmosphere anneal led to highly conducting and textured n-type MoS 2 (%50 V À1 cm À1 ) and WS 2 (%7 V À1 cm À1 ) films. [100] Amorphous As 2 S 3 and As 2 Se 3 films have also been deposited using an analogous process, [101] but attempts to deposit other main-group metal chalcogenides, such as Sb 2 S 3 and GeS x were not successful, due to the low solubility [102] The use of hydrazine as a solvent may therefore offer benefits in terms of providing for a wider range of compatible materials for deposition, and perhaps with respect to a cleaner (no carbon) and lower-temperature decomposition pathway.…”

Antenatal diagnosis of bilateral intrathoracic kidneys

“…Wet chemical approaches in producing monolayers of MoS 2 via low temperature thermal decomposition of a single source precursor containing both Mo metal and S have also been demonstrated 66, 67. In a wet chemical approach, ammonium tetramolybdate ((NH 4 ) 2 MoS 4 ) has been stirred in oleylamine and allowed to decompose at elevated temperatures 66.…”