DFT study on structural, electronic, and optical properties of cubic and monoclinic CuO

First-principles calculations were made to explore the structural, electronic, and optical properties of copper oxide (CuO) with monoclinic (m-CuO) and cubic (c-CuO) structures. We calculated the equilibrium structural parameters: lattice parameters (a, b, and c), angle β\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\beta $$\end{document}, and volume V. The obtained results were in good agreement with the experimental data reported in the literature. The cohesive energy showed that m-CuO is more stable than c-CuO. The band structure indicated that c-CuO is an indirect band gap semiconductor with a band gap of 0.87 eV along R–G, while m-CuO has a metallic behavior. Furthermore, electrovalent and covalent bonds were observed in both c-CuO and m-CuO. The linear optical properties were calculated and analyzed along different polarization directions of the incident light. The results indicated that m-CuO possesses optical anisotropic properties. In particular, c-CuO can be used as a potential UV detector material because of its high absorption coefficient (356351.3).