Polarons Explain Luminescence Behavior of Colloidal Quantum Dots at Low Temperature
| Autor: | Sravya Rao, Meenakshi Khosla, Shilpi Gupta |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Photoluminescence
Phonon Exciton FOS: Physical sciences lcsh:Medicine Physics::Optics 02 engineering and technology Polaron 01 natural sciences Article Condensed Matter::Materials Science 0103 physical sciences Mesoscale and Nanoscale Physics (cond-mat.mes-hall) 010306 general physics lcsh:Science Line (formation) Physics Multidisciplinary Condensed matter physics Condensed Matter - Mesoscale and Nanoscale Physics Condensed Matter::Other lcsh:R 021001 nanoscience & nanotechnology Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Microsecond Quantum dot lcsh:Q 0210 nano-technology Luminescence |
| Zdroj: | Scientific Reports Scientific Reports, Vol 8, Iss 1, Pp 1-12 (2018) |
| Popis: | Luminescence properties of colloidal quantum dots have found applications in imaging, light-sources, and displays. Despite wide interest, several experimental observations from these quantum dots, such as the short lifetime on the scale of microseconds and a zero-longitudinal optical phonon line in low-temperature photoluminescence spectrum, remain unexplained by existing models. Here we propose a model including the effect of solid-state environment on luminescence by capturing coherent and incoherent interactions of band-edge exciton with phonon modes. Our model predicts the formation of dressed states by coupling of the exciton with a confined acoustic phonon mode, and explains the short lifetime and the presence of the zero-longitudinal optical phonon line in the spectrum. Accounting for the interaction of the exciton with bulk phonon modes, the model also explains the experimentally observed temperature-dependence of the photoluminescence decay dynamics and temperature-dependence of the photoluminescence spectrum. 5 figures and 4 supplementary figures; Pure dephasing of dressed dark state neglected, minor changes in figures, conclusions unchanged |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|