Low-temperature wafer-scale synthesis of two-dimensional SnS₂

Abstract

Research on two-dimensional (2D) metal dichalcogenides is rapidly expanding owing to their unique characteristics that do not exist in bulk materials. The industrially compatible development of these emerging materials is indispensable to facilitate the transition of 2D metal dichalcogenides from the research stage to the practical industrial application stage. However, an industrially relevant method, i.e., the low-temperature synthesis of wafer-scale, continuous, and orientation-controlled 2D metal dichalcogenides, still remains a significant challenge. Here, we report the low-temperature (≤350 °C) synthesis of uniform and continuous n-type SnS2 thin films via the combination of atomic layer deposition (ALD) of tin oxides and subsequent sulfurization. Well-crystallized and aligned SnS2 layers parallel to the substrate are demonstrated through the phase engineering of the ALD-grown tin oxide and the substrate surface. The additional H2S plasma treatment at 300 °C leads to the formation of stoichiometric SnS2. The formation of conformal SnS2 layers over a three-dimensional undulating hole structure is confirmed, which reveals the potential for applications beyond the planar structured architecture. The present results could be a step toward the realization of 2D metal dichalcogenides in industry.

Cation-Regulated Transformation for Continuous Two-Dimensional Tin Monosulfide

“…Each layer corresponds to a (040) plane 31 of SnS for an interspacing of 2.8 Å and a (001) plane of SnS 2 for an interspacing of 5.9 Å. 4 The transformed SnS layers are observed not only near the surface but also at the interface with the SiO 2 substrate despite insufficient cycles for transformation. The transformed SnS is even observed below the SnS 2 that had not yet transformed.…”

Synthesis and Applications of Wide Bandgap 2D Layered Semiconductors Reaching the Green and Blue Wavelengths

“…This allows the formation of MoO 3 /MoS 2 heterostructures when oxidizing few-layer MoS 2 crystals. Similarly, two-step growth of 3 nm SnS 2 crystals is achieved by sulfurization of ALD-grown tin oxides (SnO and SnO 2 ) on Al 2 O 3 substrate . Two-step growth of 2D perovskites has also been reported by many groups. − Ha et al reported the synthesis of 2D perovskite nanoplatelets from 2D PbI 2 .…”

On the Contact Optimization of ALD-Based MoS2 FETs: Correlation of Processing Conditions and Interface Chemistry with Device Electrical Performance

“…In this work, atomic layer deposition (ALD) is employed for the growth of MoS 2 films. Although chemical vapor deposition (CVD) is still the preferred synthesizing technique to achieve the best quality 2D TMDCs in large areas, ,, in the quest of Ångstrøm level thickness control and highly conformal layers (suitable for 3D structures) while maintaining a low thermal budget, required for industry processes, ALD has also been gaining attention in recent years. − We comprehensively study the impact of device processing conditions on the chemistry involved at the metal-to-MoS 2 interface and connect the two to the current–voltage ( I – V ) results, obtained from electrically characterizing the fabricated FETs, with ALD-based MoS 2 films and Ti/Au contacts. In pursuit of optimizing the contacts to our MoS 2 , we investigate the influence of thermal annealing and plasma cleaning the contacts (with O 2 and Ar) on the overall device electrical performance while scaling down the Ti interlayer thickness.…”