Structural, optical and dielectric properties of (Co and Sm) co-implanting O-polar ZnO films on sapphire substrate

In this paper, molecular beam epitaxy (MBE) was used to prepare O-polar ZnO films on the sapphire substrate. Co ions and Sm ions were respectively injected into the O-polar ZnO films by ion implantation, so that Co-implanted O-polar ZnO film, Sm-implanted O-polar ZnO film, and (Co and Sm) co-implanted O polar ZnO film were prepared. We adopted X-ray diffraction (XRD), Atomic Force Microscope (AFM), Raman spectroscopy, photoluminescence spectra (PL), absorption spectroscopy and Spectroscopic Ellipsometry (SE) to study the structure, optical and dielectric properties of all samples. XRD showed that Co atoms and Sm atoms had entered the crystal lattice and the high-quality ZnO films had been prepared. Compared with the unimplanted sample, the surfaces of the implanted samples were granular and the roughness became larger. The co-implanted sample had the smaller roughness than the single-implanted samples. It was found from Raman spectra that two modes related to the LO vibration mode appeared near 50-230 cm-1 and 520-570 cm-1 after implantation. The PL spectra indicated that the intensity of the Sm-implanted sample was greater than the (Co and Sm) co-implanted sample. After ion implantation, the results measured by SE showed the band gap values of the (Co and Sm) co-implanted sample was reduced, and a transition peak around 3.15 eV appears in the second-order derivative spectra of the imaginary part epsilon 2 of the dielectric function. These paved the way for their application and development in optoelectronic devices. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

In this study, O-polar ZnO films were prepared using molecular beam epitaxy and ion implantation was used to introduce Co ions and Sm ions into the films. Various characterization techniques were employed to study the structure, optical, and dielectric properties of the samples. The results showed changes in surface roughness and dielectric properties after ion implantation, indicating potential for application in optoelectronic devices.