| 초록 |
2D transition metal dichalcogenides (TMDs) have direct bandgap energy, high electron mobility, and good optical absorption, lending themselves to potential applications in electrical devices. As a universal approach to preparing large-area 2D TMDs, the chemical vapor deposition (CVD) method largely uses metal oxide powder precursors, in which the transport of vaporized precursor has a great impact on the growth, inhibiting the realization of uniformity and reproducibility over large-area. Furthermore, defects such as grain boundaries of TMDs degrade electron devices. Here, we demonstrate an aligned growth of 2D WSe2 on the step-edges of a c-sapphire substrate using liquid precursors. The precursor salts (Na2WO4 and Na2SeO3) dissolved in DI water were spin-coated on the c-sapphire substrate, and WSe2 were grown in the CVD tube furnace with additional Se evaporation. The growth morphology, substrate surface coverage, and the degree of alignment were systemically analyzed according to the substrate temperature profile throughout the growth. Our results shed light on the fabrication of highly uniform, large-area 2D TMDs for the enhanced performance of electronic devices. |
