This study reports the successful fabrication and characterization of two-dimensional (2D) vertical heterostructures composed of a semiconducting molybdenum disulfide (MoS2) layer stacked with semimetallic platinum dichalcogenides (PtSe2 and PtTe2). The heterostructures were created using a versatile fabrication method that combines chemical vapor deposition (CVD) to grow high-quality MoS2 nanolayers with thermally assisted conversion (TAC) for the synthesis of the Pt-based layers. The final MoS2/PtSe2 and MoS2/PtTe2 heterostructures were then assembled via a dry transfer process, ensuring high structural integrity. The quality and properties of these heterostructures were investigated using a range of advanced spectroscopic techniques. Raman spectroscopy confirmed the presence of characteristic vibrational modes for each material, validating successful formation. X-ray photoelectron spectroscopy (XPS) analysis further confirmed the elemental composition and oxidation states, though it also revealed the presence of elemental Pt0 and oxidized Te+4 in the PtTe2 layer, suggesting an incomplete conversion. Importantly, the photoluminescence (PL) spectra showed a significant quenching effect, a clear sign of strong interlayer charge transfer, which is essential for optoelectronic applications. Finally, UV-Vis-NIR spectrophotometry demonstrated the combined optical properties of the stacked layers, with the Pt-based layers causing broadening and a blue-shift in the MoS2 exciton peaks, indicating altered electronic and optical behavior. This research provides valuable insights into the synthesis and fundamental properties of MoS2/PtX2 heterostructures, highlighting their potential for next-generation electronic and optoelectronic devices.
Minev et al. (Mon,) studied this question.