Rapid Trapping as the Origin of Nonradiative Recombination in Semiconductor Nanocrystals
| Autor: | Ilya Sychugov, Federico Pevere, Fatemeh Sangghaleh, Benjamin Bruhn, Jan Linnros |
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| Rok vydání: | 2018 |
| Předmět: |
Photoluminescence
Materials science 02 engineering and technology Trapping 01 natural sciences Molecular physics Condensed Matter::Materials Science symbols.namesake 0103 physical sciences Physics::Atomic Physics Electrical and Electronic Engineering 010306 general physics Quantum tunnelling Condensed Matter::Quantum Gases Auger effect Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials Quantum dot symbols Quantum efficiency 0210 nano-technology Luminescence Excitation Biotechnology |
| Zdroj: | ACS Photonics. 5:2990-2996 |
| ISSN: | 2330-4022 |
| DOI: | 10.1021/acsphotonics.8b00581 |
| Popis: | We demonstrate that nonradiative recombination in semiconductor nanocrystals can be described by a rapid luminescence intermittency, based on carrier tunneling to resonant traps. Such process, we call it “rapid trapping (blinking)”, leads to delayed luminescence and promotes Auger recombination, thus lowering the quantum efficiency. To prove our model, we probed oxide- (containing static traps) and ligand- (trap-free) passivated silicon nanocrystals emitting at similar energies and featuring monoexponential blinking statistics. This allowed us to find analytical formulas and to extract characteristic trapping/detrapping rates, and quantum efficiency as a function of temperature and excitation power. Experimental single-dot temperature-dependent decays, supporting the presence of one or few resonant static traps, and ensemble saturation curves were found to be very well described by this effect. The model can be generalized to other semiconductor nanocrystals, although the exact interplay of trapping/detra... |
| Databáze: | OpenAIRE |
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