Rhombohedral-stacked bilayer transition metal dichalcogenides for high-performance atomically thin CMOS devices

Van der Waals coupling with different stacking configurations is emerging as a powerful method to tune the optical and electronic properties of atomically thin two-dimensional materials. Here, we investigate 3R-stacked transition-metal dichalcogenides as a possible option for high-performance atomically thin field-effect transis-tors (FETs). We report that the effective mobility of 3R bilayer WS2 (WSe2) is 65% (50%) higher than that of 2H WS2 (WSe2). The 3R bilayer WS2 n-type FET exhibits a high on-state current of 480 mu A/mu m at Vds = 1 V and an ultralow on-state resistance of 1 kilohm center dot mu m. Our observations, together with multiscale simulations, reveal that these improvements originate from the strong interlayer coupling in the 3R stacking, which is reflected in a higher conductance compared to the 2H stacking. Our method provides a general and scalable route toward advanced channel materials in future electronic devices for ultimate scaling, especially for complementary metal oxide semiconductor applications.

Automated summary

Van der Waals coupling with different stacking configurations is a powerful method to tune the optical and electronic properties of two-dimensional materials. This study focuses on investigating 3R-stacked transition-metal dichalcogenides as a possible option for high-performance field-effect transistors. The results show that 3R bilayer WS2 (WSe2) exhibits higher effective mobility and improved conductivity compared to the 2H stacking. These improvements originate from the strong interlayer coupling in the 3R stacking. This method provides a scalable route for advanced channel materials in electronic devices.