Seeded Solid-Phase Epitaxy of Wafer-Scale 2H-MoTe ₂ Single-Crystal Arrays through Spatially Confined Single Nucleation

Two-dimensional (2D) semiconductors offer opportunities for the development of post-Moore information devices due to their exceptional properties. Analogous to silicon-based technologies, the fabrication of wafer-scale single crystals stands as a prerequisite for their large-scale application. Herein, we demonstrate the seeded solid-phase epitaxial growth of wafer-scale single-crystalline 2H-MoTe₂ arrays on diverse substrates through spatially confined single nucleation. By precisely controlling the nucleation and atomic diffusion processes, the production efficiency and quality of wafers have been significantly improved, laying the foundation for their practical applications in high-performance field-effect transistors and photodetectors. In particular, the in situ integrated 2H-MoTe₂/Si p-n photodiode arrays exhibit a high photon-triggered on/off ratio of 10⁶ and a detectivity exceeding 3 × 10¹² Jones, which solves the arrays' crosstalk problem and enables near-infrared optical communication and optical imaging. This work offers a pathway toward large-scale production and integration of 2D semiconductors in the form of single crystals.