Investigating the impact of growth temperature on the direct integration of pure phase 2H-MoTe2 with Si(1 1 1) using molecular beam epitaxy

Group-VI transition metal dichalcogenides (TMDCs) have garnered significant attention due to their novel properties in the two-dimensional realm. Among these TMDCs, MoTe2 is a particularly intriguing material with a small difference between Gibbs free energies of its semiconducting and semimetallic phases, rendering it suitable for a wide array of applications. In this study, we report the molecular beam epitaxy (MBE) growth of 2H-MoTe2 directly on a silicon (1 1 1) substrate, which holds great significance due to its compatibility with the existing integrated circuit industry. By employing a growth strategy involving a Te-rich silicon surface, we achieved the growth of high-quality, phase-pure 2H-MoTe2 films. The effect of growth temperature on the film quality was investigated, revealing that the growth at 450 °C led to highly crystalline and layered growth. The thickness, roughness and stoichiometry of the grown films were characterized using spectroscopic ellipsometry, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). Raman spectroscopy confirmed the presence of the desired 2H-phase for the grown films. The direct integration of MoTe2 with silicon opens up exciting possibilities for its utilization in nanoelectronics and optoelectronics devices.