Relaxation Dynamics of Excited States in Mn2+-Doped ZnCdS (Core)/ZnS (Shell) Quantum Dots Ions in Propylene Carbonate

Autor:	Ivan V. Shelaev, Yu. A. Kabachiy, S. Yu. Kochiev, Andrei Kostrov, Fedor E. Gostev, O. Yu. Antonova, Pyotr M. Valetsky, V. A. Nadtochenko, Arseniy V. Aybush
Rok vydání:	2020
Předmět:	010302 applied physics 010304 chemical physics Absorption spectroscopy Chemistry Exciton Quantum yield 01 natural sciences Molecular physics chemistry.chemical_compound Quantum dot Excited state 0103 physical sciences Propylene carbonate Physical and Theoretical Chemistry Absorption (electromagnetic radiation) Luminescence
Zdroj:	High Energy Chemistry. 54:421-426
ISSN:	1608-3148 0018-1439
Popis:	It has been shown that luminescence in Mn@Zn0.49Cd0.51S/ZnS quantum dots (QDs) in propylene carbonate is due to a single Mn2+(4T1 → 6A1) band and has a quantum yield of ~24%. The Mn2+(4T1) level is excited through the light absorption in the exciton absorption bands of Zn0.49Cd0.51S/ZnS. The femtosecond dynamics of the difference spectra of Mn@Zn0.49Cd0.51S/ZnS QDs show fast relaxation of the exciton on the subpicosecond–picosecond timescale. At delay times in picosecond range, the band of stimulated luminescence has been detected in difference absorption spectra in the Mn2+(4T1 → 6A1) transition region. A qualitative hypothetical mechanism of nonradiative energy transfer from the exciton to Mn2+(4T1) involving the Auger transition in the trap states has been proposed. The assumption solves the problems of the energy excess of 0.98 eV in the energy transfer to the 3d5 level of Mn and of the conservation of the total spin of the system.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::3853875acef80c6b70fc346f9eab439a https://doi.org/10.1134/s0018143920060090 Zobrazit plný text záznamu Plný text ve formátu PDF Plný text ve formátu HTML
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