Electronic and optical properties of pure and Ce3+-doped MgS single crystals: A first-principles prediction

The electronic and optical properties for pure and Ce3+-doped MgS crystals have been investigated by using the first-principles total energy calculations. The results show that MgS:Ce has a direct band gap of 2.38 eV, and the top of the valence band is determined by S 3p and Ce 4f states and the bottom of the conduction band is determined by Mg 2p, 3s and Ce 4f, 5d states, respectively. The Ce–S bond shows more ionic character than the Mg–S bond. Our results suggest that the green emission from MgS:Ce is produced by doped cerium. Furthermore, it is shown that MgS:Ce is a promising dielectric material.