CVD-growth and optoelectronic characterization of 2D MoS2/ReS2 vertical heterostructures with reverse stacking sequence

Vertically stacked 2D heterostructures (HSs) created via in-plane isotropic/anisotropic 2D transition-metal dichalcogenides (TMDCs) have recently attracted wide attention owing to unique interlayer coupling characteristics and possess a perspective potential in advanced photodetectors. However, the fabrication and interlayer exciton behavior of such vertical HS remain an enormous challenge. Herein, we report on the demonstration of two kinds of 2D MoS2/ReS2-based vertical HSs by altering the Re-based precursors during the one-step CVD process. The related interlayer excitons, interlayer coupling interaction, and charge separation are elucidated by Raman-photoluminescence spectroscopy and photoresponse measurement. Lastly, the possible growth mechanism of these two types of vertical HSs has been discussed on the basis of the evaporation temperature difference between Re-based precursors and Mo foil. Such a study provides a feasible and controllable strategy for the fabrication of in-plane isotropic/ anisotropic TMDC HSs with different phase structures.

Automated summary

Vertically stacked 2D heterostructures created from in-plane isotropic/anisotropic 2D transition-metal dichalcogenides have attracted attention for their unique interlayer coupling characteristics and potential applications in advanced photodetectors. However, fabricating and understanding the behavior of interlayer excitons in such structures remain challenging. In this study, we demonstrate two types of vertical heterostructures based on 2D MoS2/ReS2 by altering the Re-based precursors during the one-step CVD process. The interlayer excitons, interlayer coupling interaction, and charge separation are investigated using Raman-photoluminescence spectroscopy and photoresponse measurements. The possible growth mechanism of these structures is discussed based on the temperature difference between Re-based precursors and Mo foil. This study provides a feasible and controllable strategy for fabricating in-plane isotropic/anisotropic TMDC heterostructures with different phase structures.