Control of Lateral Epitaxial Nanothin β-In₂Se₃ Grown by Molecular Beam Epitaxy: Implications in Fabricating of Next-Generation Transistors

High Resolution Image Download MS PowerPoint Slide This study was meticulously conducted, delving into the epitaxial growth of nanothin β-In 2 Se 3 films on sapphire (0001) using molecular beam epitaxy. The growth temperature was carefully set at 480 °C, and the selenium to indium flux ratio ( R Se/In ) was systematically varied from 1 to 100. The phase transformation from γ-In 2 Se 3 to β-In 2 Se 3 was precisely controlled by manipulating the R Se/In and confirmed through Raman scattering measurements and synchrotron-based grazing-incidence wide-angle X-ray scattering. The surface morphology for various R Se/In of In 2 Se 3 was analyzed by atomic force microscopy (AFM). The lowest surface roughness is around 0.58 nm, which is achieved under the R Se/In = 60 growth condition. The nanothin β-In 2 Se 3 film with a layer-by-layer atomic arrangement was verified by high-resolution transmission electron microscopy. According to the experimental results, the growth dynamics of In 2 Se 3 are proposed to be step-flow growth and horizontal growth under R Se/In 45 and 60 conditions, respectively. This research underscores the control of the growth mechanism by Se/In flux and its role in facilitating the In 2 Se 3 epitaxy for integration in the development of 2D-materials-based future electronic devices.