Alloyed core/doped shell MnxZn1−xSe/ZnSe:Mn2+ nanocrystals: steady-state and time-resolved spectroscopy
| Autor: | Sébastien Lamarre, Claudine Nì. Allen, Anna M. Ritcey |
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| Rok vydání: | 2017 |
| Předmět: |
Materials science
Photoluminescence Doping Biophysics Analytical chemistry Phosphor 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Mole fraction 01 natural sciences Biochemistry Atomic and Molecular Physics and Optics 0104 chemical sciences Ion Nanocrystal Excited state Atomic physics Time-resolved spectroscopy 0210 nano-technology |
| Zdroj: | Journal of Luminescence. 181:421-426 |
| ISSN: | 0022-2313 |
| DOI: | 10.1016/j.jlumin.2016.09.059 |
| Popis: | Steady state and time-resolved optical properties of alloyed core/doped shell MnxZn1−xSe/ZnSe:Mn2+ nanocrystals with x between 0.2 and 1 were studied. The emission from Mn2+ ions at ~580 nm is predominant for higher MnSe mole fractions in the core (higher x). At lower fractions, the ZnSe excitonic emission is also present while the Mn2+ emission shifts to ~560 nm. The ratio of photoluminescence intensity of these emission bands depends on the composition of the alloyed core. The excited state lifetime of Mn2+ ions is also strongly dependent on the core composition, ranging from 300 μs for small MnSe mole fractions down to 65 μs for x=1. This is attributed to the long-range strain caused by a lattice mismatch of more than 4% at the core/shell interface. For x ≤ 0.6 , an additional lifetime, depending on the presence of an extra electron within the nanocrystals, was measured in the hundreds of nanoseconds range. A 4-level dynamic model is proposed to explain this observation. |
| Databáze: | OpenAIRE |
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