Creation of storage centers in CsBr:Eu2+ needle image plates by vacuum ultraviolet radiation

Abstract

In this study, the photostimulated luminescence of the CsBr: Eu 2+ needle image plates ͑NIPS͒ after vacuum ultraviolet ͑VUV͒ irradiation and their photoluminescence under VUV and UV excitation were investigated. It was shown that the photostimulable storage centers arise almost exclusively due to irradiation of the CsBr:Eu NIPs in the spectral lines of creation of the 4p 5 5s anion excitons, and not in the region of interband transitions of CsBr. The explanation of the results is based mainly on the radiative and nonradiative decay of the self-localized e +Br 2 − excitons.

Luminescence of Cu+and Cu2+Ions in CsBr Crystals

“…The possible reasons for the existence of two bands of Cu + and Cu 2+ emission in CsBr crystal are as follows: (i) the existence of on-and off-centre configurations of the relaxed excited state of Cu + and Cu 2+ ions due to very large difference of the ionic radius of Cu + and Cu 2+ ions (0.77 Å and 0.73 Å, respectively) in sixfold coordi-nation and Cs + cations (1.67 Å) [7], (ii) the formation of the dimer or other complex Cu + and Cu 2+ centers [6]. The existence of both considered models in Cu-doped alkali-halides has been discussed in works [6,[10][11][12].…”

“…The luminescence of Eu 2+ ions in CsBr:Eu host was also studied in our previous paper [7] and later in the CsBr:Eu 2+ needle image plates (NIP) [8] under excitation by SR in the CsBr fundamental absorption range. The creation of excitons localized around Eu 2+ ions was noted [7].…”

“…The luminescence of Eu 2+ ions in CsBr:Eu host was also studied in our previous paper [7] and later in the CsBr:Eu 2+ needle image plates (NIP) [8] under excitation by SR in the CsBr fundamental absorption range. The creation of excitons localized around Eu 2+ ions was noted [7]. In work [8] it was shown that photostimulable storage centers arise exclusively under the excitation of bands related to creation of the 4p 5 5s excitons.…”

The role of oxygen in the photostimulated luminescence process of europium doped potassium chloride

“…On the other hand, according to Itoh (Itoh, 1982), the photostimulable centers in alkali halides can also be created by ionizing radiation by the process in which a self-trapped exciton undergoes an isomeric transformation to an F-H pair. Recently Weidner et al (Weidner et al, 2009) report that the storage centers in CsBr:Eu 2+ are formed via the nonradiative decay of the dihalide selflocalized excitons close to the Eu 2+ -containing emission centers, providing the latest evidence in support of the Itoh mechanism. Itoh’s model suggests that electron and hole storage centers created by ionizing radiation are spatially correlated, which has been confirmed by von Seggern et al (von Seggern et al, 1988).…”