Tungsten doping-induced phase transition in CVD-grown MoS2 bilayers
Source abstract
Abstract
Controlling the crystal phase of two-dimensional (2D) transition metal dichalcogenides (TMDs) is essential for tailoring their optical and electronic properties. While phase transitions in monolayer TMDs and semiconductor-to-metal conversions have been widely studied, structural transitions between semiconducting polytypes - particularly in bilayer (2L) systems - remain underexplored. Here, we demonstrate a tungsten (W) doping-induced phase transition from non-centrosymmetric AA stacking to centrosymmetric AB’ in 2L MoS2 synthesized by chemical vapor deposition (CVD). Using polarization-resolved second harmonic generation (SHG) and low-frequency Raman spectroscopy, we identify a phase transition correlated with increasing W concentration. The dilute W-doped 2 L system exhibits a vanishing SHG signal and a stiffening of the layer-breathing (LB) vibrational mode, in contrast to undoped samples with strong SHG and a softer LB mode. Aberration corrected scanning transmission electron microscopy (AC-STEM) demonstrates the spatial distribution of W concentration and associated structural changes. These findings highlight W-doping as an effective strategy for inducing phase transitions in 2L TMDs, opening new possibilities for engineered heterostructures, phase-controlled device applications or as a source of single photon emitters.
Source: openalex_inverted_index · Quality: baseline
Research context
OpenAlex topics: 2D Materials and Applications · Graphene research and applications · Nanowire Synthesis and Applications
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (69)
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