Semimetallic bands derived from interlayer electrons in the quasi-two-dimensional electride Y2 C

Two-dimensional (2D) electrides are a new concept material in which anionic electrons are confined in the interlayer space between positively charged layers. We have carried out angle-resolved photoemission spectroscopy measurements on Y2C, which is a possible 2D electride, in order to verify the formation of 2D electride states in Y2C. We clearly observe the existence of semimetallic "electride bands" near the Fermi level, as predicted by ab initio calculations, which conclusively demonstrates that Y2C is a quasi-2D electride with electride bands derived from interlayer anionic electrons.