High-Performance p-Type Field-Effect Transistor Based on WS₂ Monolayer Prepared by Liquid-Phase-Assisted Space-Confined CVD

Although some progress has been made in the synthesis of p -type two-dimensional (2D) WS 2, the hole mobility of WS 2 field-effect transistors (FETs) is still very low, significantly impeding its application in logic complementary circuits. In this study, p -type 2D WS 2 has been successfully prepared by liquid-phase assisted space-confined chemical vapor deposition (LASCVD) method and machine learning (ML) has been employed to optimize the process parameters of the growth of WS 2 nanosheets. Results show that, under the optimal growth conditions, the maximum domain size of WS 2 monolayer reaches 475 μm. Additionally, W vacancies in WS 2 nanosheets have been observed through STEM-HAADF, Raman and PL analysis, contributing to the p -type characteristic of 2D WS 2 . Moreover, p -type high-performance FETs based on the WS 2 monolayer have been fabricated, exhibiting a high hole mobility of 46.87 cm 2 V –1 s –1 and an on/off ratio of 10 5 . This study provides a promising direct synthesis method for p -type 2D TMDCs.