Evidence for Anionic Excess Electrons in a Quasi-Two-Dimensional Ca_2N Electride by Angle-Resolved Photoemission Spectroscopy

摘要

Angle-resolved photoemission spectroscopy (ARPES) study of a layered electride Ca_2N was carried out to reveal its quasi-two-dimensional electronic structure. The band dispersions and the Fermi-surface map are consistent with the density functional theory results except for a chemical potential shift that may originate from the high reactivity of surface excess electrons. Thus, the existence of anionic excess electrons in the interlayer region of Ca_2N is strongly supported by ARPES.