This renewal proposal focuses on a study of the optical and electronic properties of alkalides, electrides and mixed systems to determine the nature of electron-electron interactions in crystalline solids with weakly trapped electrons, factors which lead to electron spin pairing, and the nature of metal-non metal transitions. Thin films, microcrystalline films, and single crystals of these materials will be prepared, and their emission-, reflectance-, transmission-, and fluorescence-spectra studied. The electrical conductivity and impedance spectroscopy of powders and single crystals will be determined, and their photoelectron and thermionic electron emission investigated.
