On the L‐Bands and the First Exciton Bands in the Photoemission Spectra of Alkali Iodides

Abstract

The photoemission spectra of NaI, KI, RbI and CsI are investigated experimentally. Besides the bands already revealed by optical absorption measurements and confirmed by photoemission studies, the L,-L,-bands in NaI, the L,-band in RbI, and the fine structure of the El-bands in K I and RbI are observed. I n CsI electron emission is detected corresponding to the first exciton band in the absence of F-centres. The very intense "extra"-bands occurring in the absorption spectra are not found.On a analys6 au moyen de spectres de photobmission des cristaux de NaI, KI, RbI et CsI. En plus des bandes d6ja r6v616es par absorption optique et confinnbes par photobmission, ont 6th mises en 6vidence lea bandes Lx-L4 du NaI, la bande L4 du RbI e t la structure fine des bandes El du K I et RbI. Pour le CsI on a dbtect6 1'6mission dectronique en absence des centres F et on a remerqub que les trbs intenses "extra"-bandes, qui apparaissent dans les spectres d'absorption, ne s'observent pas en photobmission.