Monolayer WS₂: Ultra-high mobility semiconductor for 2D transistors

2D semiconductors possess dangling-bond free surfaces and thus can preserve their carrier mobilities down to the monolayer limit. This unique characteristic offers a promising pathway to future ultra-scaled transistors in which 2D materials replace silicon as channel materials. However, the mobility of 2D semiconductors still remains much lower than that of silicon. By combining a high-throughput screening approach and advanced transport calculations based on the ab initio Boltzmann transport equation, we have performed a search for high mobility 2D semiconductors and identified several promising candidates. Among those, monolayer WS₂ is the top candidate, exhibiting a theoretical phonon-limited hole mobility in excess of 1300 cm²/Vs after including both GW corrections and dipole and quadrupole corrections. The present work suggests that WS₂ can be ideal for channel of high-performance 2D transistors with Ohmic contacts and low defect density [npj Comput. Mater. 10, 229 (2024); DOI: 10.1038/s41524-024-01417-0].