Attractive versus Repulsive Excitonic Interactions of Colloidal Quantum Dots Control Blue- to Red-Shifting (and Non-shifting) Amplified Spontaneous Emission
| Autor: | Ozan Yerli, Halime Gul Yaglioglu, Burak Guzelturk, Ahmet Fatih Cihan, Hilmi Volkan Demir, Yusuf Kelestemur, Ayhan Elmali, Ulaş Kürüm |
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| Přispěvatelé: | Demir, Hilmi Volkan |
| Rok vydání: | 2013 |
| Předmět: |
Wave-guides
Amplified spontaneous emission TPA cross sections Spontaneous emission Luminescence of organic solids Physics::Optics CdSe/CdS quantum dots Semiconductor Nanocrystals Two-photon absorption amplified spontaneous emission Two-photon absorptions Regime Computer Science::Networking and Internet Architecture Semiconductor quantum dots two-photon absorption General Materials Science Stimulated emission Physical and Theoretical Chemistry Absorption (electromagnetic radiation) Physics Energy Colloidal quantum dots business.industry Excitonic interaction near-unity efficiency Two photon processes Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Dynamics Nanocrystals Wavelength Light Amplification Quantum dot exciton-exciton interactions Amplified spontaneous emissions Optoelectronics Stimulated-emission Quantum efficiency Optical Gain business Quantum mechanical model Inverted Core/shell Nanocrystals Confinement Light polarization |
| Zdroj: | Journal of Physical Chemistry Letters The Journal of Physical Chemistry Letters |
| ISSN: | 1948-7185 |
| DOI: | 10.1021/jz402211m |
| Popis: | Tunable, high-performance, two-photon absorption (TPA)-based amplified spontaneous emission (ASE) from near-unity quantum efficiency colloidal quantum dots (CQDs) is reported. Besides the absolute spectral tuning of ASE, the relative spectral tuning of ASE peak with respect to spontaneous emission was shown through engineering excitonic interactions in quasi-type-II CdSe/CdS core/shell CQDs. With core-shell size adjustments, it was revealed that Coulombic exciton-exciton interactions can be tuned to be attractive (type-I-like) or repulsive (type-II-like) leading to red- or blue-shifted ASE peak, respectively, and that nonshifting ASE can be achieved with the right core-shell combinations. The possibility of obtaining ASE at a specific wavelength from both type-I-like and type-II-like CQDs was also demonstrated. The experimental observations were supported by parametric quantum-mechanical modeling, shedding light on the type-tunability. These excitonically engineered CQD-solids exhibited TPA-based ASE threshold as low as 6.5 mJ/cm2 under 800 nm excitation, displaying one of the highest values of TPA cross-section of 44 660 GM. © 2013 American Chemical Society. |
| Databáze: | OpenAIRE |
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