Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7840134 | Journal of Luminescence | 2018 | 16 Pages |
Abstract
Photoluminescence of Ce3+- and Pr3+-activated Sr2GeO4 powders was measured between 17 and 600â¯K. For both ions strong 4fnâ15dnâ4fn (d-f) emission is observed at low temperatures, around 410â¯nm (Ce3+) and 280â¯nm (Pr3+). The Ce3+ d-f emission quenches starting at 150â¯K and disappearing completely just above room temperature. Pr3+ d-f luminescence shows an onset of quenching also around 150â¯K and disappears completely between 250 and 300â¯K. For Pr3+ quenching of the d-f emission was connected with an increasing intensity of the 3P0 luminescence at first and 1D2 emission at even higher temperatures. Both these 4fnâ4fn emissions were observed up to 600â¯K. Based on the similar quenching temperatures, thermally stimulated photoionization of the 5d electrons from 5d level of Ce3+ or Pr3+ to the conduction band is proposed as the most probable mechanism for quenching of the d-f emissions.
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Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Karolina Fiaczyk, Shun Omagari, Andries Meijerink, Eugeniusz Zych,