centre de luminescence

CONT: Lorsque des paires électron-trou sont créées, ces charges se retrouvent rapidement piégées sur ces niveaux localisés appelés centres de luminescence.
OBS: Scintillateurs inorganiques. Dans ces scintillateurs, l'émission de lumière est généralement due à la présence d'un dopant en faible quantité (comme le thallium dans le Nal ou le Csl) qui induit dans le cristal des niveaux localisés à l'intérieur du gap [...]

CONT: In liquids and solids (as well as molecular gases), the radiation is emitted in bands due to transitions between closely spaced levels. Except in a few special cases, the radiation is emitted by isolated levels associated with activators, usually present in very small concentrations in a matrix or host material. These luminescence centers can be the activator ion itself, or a disturbance of the lattice caused by the activator ion. They correspond to the chromophores of chemists. In the ""pure"" luminescent materials, such as platinocyanates and uranyl compounds, the centers are ions with unfilled inner electron shells.