Molecular beam epitaxy of high-quality CuI thin films on a low temperature grown buffer layer

• DOI: 10.1063/5.0007389
• Publication Date: 2020-05-13T16:56:06Z
• Authors: S. Inagaki; M. Nakamura; N. Aizawa; L. C. Peng; X. Z. Yu; Y. Tokura; M. Kawasaki
• Keywords: Atomic layer epitaxy

We show a growth of high-quality thin films wide bandgap semiconductor copper iodide (CuI) on Al2O3 substrates by molecular beam epitaxy. Employing buffer layer deposited at lower temperature (160 °C) prior to the main growth, maximum is elevated up 240 °C, resulting in significant improvement crystallinity as verified sharp x-ray diffraction peaks well step-and-terrace structure observed atomic force microscopy. Optimum more intense free exciton emission photoluminescence spectra than others, implying suppression defects. These results indicate that fabrication process developed this study quite effective realizing CuI films.