Zn ions-assisted growth of single-crystalline 2D WSe 2 with high quality via chemical vapor deposition

Abstract 2D WSe 2 , as a vital member of p-type transition metal dichalcogenides, exhibits exceptional electronic properties, making it particularly appealing for electronic applications. However, the major bottleneck requires the growth of large-area WSe 2 single crystals with low defect density, which is essential for practical use. In this study, we present a straightforward atmospheric-pressure chemical vapor deposition method that incorporates Zn ions to facilitate the growth of large-area WSe 2 single crystals with 501 μ m (average size is of 236 μ m). The as-grown WSe 2 exhibits high crystallinity and low defect density ranging from 2.4 × 10 12 cm −2 –3.9 × 10 12 cm −2 . Calculations indicate that the presence of Zn ions effectively reduces the reaction free energy associated with the nucleation and growth of WSe 2 , serving as a critical factor that enhances the growth process. The fabricated WSe 2 field-effect transistors exhibit exceptional electrical performance, achieving a maximum field-effect mobility of 46.02 cm 2 V −1 s −1 and an on/off current ratio of 10 6 . This work provides an effective approach for growing high-quality WSe 2 and holds promise for advancing nanoelectronics with superior performance.