Influence of samarium on optical absorption in thin films of the solid electrolyte RbAg4I5

The fundamental optical absorption of films of the solid electrolyte RbAg4I5 electrolyte films decreases (by approximately 25%) after vacuum evaporation of Sm films onto them, and a broad strong-absorption band with a maximum at 2.4 eV appears within the bad gap. The films bleach after 5-10 days in dry air. The observed phenomena are attributed to a high concentration (similar to 3 x 10(20) cm(-3)) of point defects, including F-centers, in nonstoichiometric RbAg,I,:Sm, and also to the oxidation of Sm, In colored films the ionic conductivity is sigma similar or equal to 0.9 sigma(0), and in bleached films it is close to the initial value sigma(0). (C) 1997 American Institute of Physics.