The radiationless relaxation pathways leading to the quenching of 3P0 emission and subsequent atypical single red luminescence from 1D2 level in CaTiO3:Pr3+ are studied under UV excitation. Self-trapped excitons are shown to participate in the relaxation process and Pr3+/Ti4+Pr4+
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The radiationless relaxation pathways leading to the quenching of 3P0 emission and subsequent atypical single red luminescence from 1D2 level in CaTiO3:Pr3+ are studied under UV excitation. Self-trapped excitons are shown to participate in the relaxation process and Pr3+/Ti4+Pr4+/Ti3+ charge transfer state (CTS) is proposed as the final relaxation channel to the emitting 1D2 level. This mechanism is supported by EPR investigations showing an increase of paramagnetic [Pr4+Ti3+O3]+ clusters upon optical excitation in the CTS.
Keywords: CaTiO3:Pr3+; Charge transfer states; EPR; Excitons; Photoluminescence; Relaxation
PACS: 78.55.Hx; 76.30.Kg@en
