Electronic structures of two-dimensional hydrogenated bilayer diamond films with Si dopant and Si-V center

The structural, electronic and optical properties of two-dimensional hydrogen-terminated bilayer diamond films (2D-HBDF) with silicon (Si) dopant and silicon-vacancy (Si-V) center are investigated by first-principles calculations. The two positions of substitutional Si are energetically favorable with similar band structures compared to the pristine 2D-HBDF. For Si-V center, the flat intermediate bands originated from the complex impurities appear in band gap. Especially, the ground state of paramagnetic or nonmagnetic for the case of Si-V is dependent on the distributions of Si dopant and vacancy. The calculated optical absorptions with relating to Si-V center show a high intensity in the visible light region. It reveals that the introducing vacancy (substituted Si) and their positions play an important role in modulating the electronic and optical properties of 2D-HBDF, which are helpful to construct novel low-dimensional diamond-based optoelectronic devices applied in extreme environments.