Quantum computational insights into electronic and optical properties of LnOIs for fundamental and technological applications

Besides their fundamental significance as f-electron materilas, lanthanide compounds have remarkable interest as potential candidates for catalytic, luminescent, optical communication, spintronics, energy, and biomedical applications. This study reports on the systematic quantum computational analysis on the geometrical structure properties, phonon vibrational, electronic, and light-assisted optical properties of two compounds of the lanthanide oxyhalides family, LnOI (Ln = La, Sm). The reported vibrational properties are phonon energy spectra and phonon density of states, the optical properties include complex dielectric parameter, reflectivity, index of refraction, absorption coefficient, loss function, extinction coefficient, and optical conductivity. For the required results on the targeted properties, the first-principles procedure based on Kohn-Sham density functional theory is employed. To account for the electronic exchange correlations, general gradient approximation within Hubbard model is used. The computed results predict the wide bandgap semiconducting nature of LnOIs with bandgaps of 3.44 eV for LaOI and 3.5 eV for SmOI. The optoelectronic properties reveal prominent feature in the visible and high energy regions, thus leading to potential implications to high-speed, high-power optoelectronics, and lighting devices.