The carrier trapping and recombination mechanisms occurring in Ce-doped silica fibers, produced by a sol–gel technique, are investigated by combining temperature-dependent steady-state X-ray-excited luminescence, wavelength- and time-resolved scintillation measurements, and wavelength-resolved thermally stimulated luminescence, focusing especially on the temperature range from 10 to 320 K. The scintillation decay features a decay time of the order of tens of nanoseconds, characteristic of the parity- and spin-allowed 5d–4f radiative transition of Ce3+ ions. In addition, a slow and complex decay contribution in the microsecond timescale is detected. We interpret these features as due to the radiative recombination at Ce centers of carriers freed from a continuous distribution of trapping sites in the forbidden gap as well as to the occurrence of an athermal tunneling recombination process between traps and Ce3+ ions. This interpretation is reinforced by good agreement between independent evaluations of trap depths and lifetimes obtained by both the numerical analysis of scintillation time decays and thermally stimulated luminescence experiments.

Cova, F., Moretti, F., Dujardin, C., Chiodini, N., Vedda, A. (2021). Trapping Mechanisms and Delayed Recombination Processes in Scintillating Ce-Doped Sol–Gel Silica Fibers. JOURNAL OF PHYSICAL CHEMISTRY. C, 125(21), 11489-11498 [10.1021/acs.jpcc.0c11073].

Trapping Mechanisms and Delayed Recombination Processes in Scintillating Ce-Doped Sol–Gel Silica Fibers

Cova, Francesca
Primo
;
Moretti, Federico
Secondo
;
Chiodini, Norberto;Vedda, Anna
Ultimo
2021

Abstract

The carrier trapping and recombination mechanisms occurring in Ce-doped silica fibers, produced by a sol–gel technique, are investigated by combining temperature-dependent steady-state X-ray-excited luminescence, wavelength- and time-resolved scintillation measurements, and wavelength-resolved thermally stimulated luminescence, focusing especially on the temperature range from 10 to 320 K. The scintillation decay features a decay time of the order of tens of nanoseconds, characteristic of the parity- and spin-allowed 5d–4f radiative transition of Ce3+ ions. In addition, a slow and complex decay contribution in the microsecond timescale is detected. We interpret these features as due to the radiative recombination at Ce centers of carriers freed from a continuous distribution of trapping sites in the forbidden gap as well as to the occurrence of an athermal tunneling recombination process between traps and Ce3+ ions. This interpretation is reinforced by good agreement between independent evaluations of trap depths and lifetimes obtained by both the numerical analysis of scintillation time decays and thermally stimulated luminescence experiments.
Articolo in rivista - Articolo scientifico
scintillation, optical fibers, silica, sol-gel, rare-earths, defects;
English
19-mag-2021
2021
125
21
11489
11498
none
Cova, F., Moretti, F., Dujardin, C., Chiodini, N., Vedda, A. (2021). Trapping Mechanisms and Delayed Recombination Processes in Scintillating Ce-Doped Sol–Gel Silica Fibers. JOURNAL OF PHYSICAL CHEMISTRY. C, 125(21), 11489-11498 [10.1021/acs.jpcc.0c11073].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/315610
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