Details

Autor(en) / Beteiligte

• Baran, M.
• Kissabekova, A.
• Krasnikov, A.
• Vasylechko, L.
• Zazubovich, S.
• Zhydachevskyy, Ya

Titel

On the excitation mechanism of the Bi3+ - Related localized exciton luminescence in Bi3+ - Doped aluminum garnets

Ist Teil von

• Journal of luminescence, 2023-11, Vol.263, p.120154, Article 120154

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2023

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• Microcrystalline powders of Bi3+-doped Y3Al5O12 and Lu3Al5O12 garnets have been studied by the X-ray diffraction, steady-state and time-resolved photoluminescence, and thermally stimulated luminescence methods. The conclusion is made that the excitation spectra of the Bi3+-related visible exciton-like emission of these compounds, which are located in the 4–6 eV energy range, cannot be explained by the charge-transfer transitions between the energy levels of Bi3+ and the conduction or valence band of the host, whose energies exceed 6 eV. To explain the features observed, this emission is suggested to appear due to the photostimulated electron transfer from the ground state of a Bi3+ ion to defect levels located in the band gap, resulting in the creation of temporary pairs of electron centers and hole Bi4+ centers. A hole delocalization from the Bi4+ ion to the neighboring oxygen O2− ion is also suggested, resulting in the creation of the {O− - Bi3+}-type hole center. As a result of the electron recombination with this hole center, the exciton localized around the Bi3+ ion is formed whose radiative decay is accompanied with the visible emission. •Microcrystalline powders of Y3Al5O12:Bi and Lu3Al5O12:Bi are studied by XRD, PL,TSL.•harge-transfer transitions between Bi3+ and conduction or valence band do no occur.•No stable electron and hole centers are optically created in Bi3+-related absorption bands.•Mechanism of photostimulated creation of temporary electron and hole centers is proposed.•Mechanism of Bi3+-related visible exciton-like emission is proposed for such compounds.