BARRIER PHOTO-EMF STUDIES OF ELECTRONIC-TRANSITIONS IN ALPHA-RBAG4I5

A study has been made of the photo-emf of alpha-RbAg4I5 superionic cry stals exposed to light from the impurity excitation region. The effect s of local light irradiation and silver saturation on the photo-emf ex citation spectrum were investigated. It was found that irradiation wit h light having energies 2.78 eV and 2.92 eV causes color centers forma tion in the crystals. Illumination intensity and time dependences of t he photo-emf for the main excitation bands were measured at room tempe rature. The estimation of the photon capture cross sections for the el ectronic transitions gives values of the order ofmagnitude of 10(-7) c m(2). A mechanism for the origin of the photo-emf is proposed.