Le rôle des excitons et des lacunes cationiques dans les proprietés luminescentes de l';iodure de césium

Abstract

Correlations between the 3470-Å exciton component and the 4300-Å emission owing to Z center (assocn. of cationic valency and divalent ion)have been studied in purified CsI. Self-trapped holes (VK center) are unstable >86°K and recombine with electrons in the Z center (thermoluminescence at 4300 Å). Conversely ir stimulation allows the trapped electron to recombine with the VK center giving the exciton type emission at 3470 Å. Decay times and yields are different with ionizing (γ-, β-, α- and x-ra ys) or uv radiation. Both thermo-and photocurrents are observed.