Auger-recomination in self-assembled quantum dots

自组装量子点中的俄歇复合

• 批准号: 383065199
• 负责人: Privatdozent Dr. Martin Geller
• 金额: --
• 依托单位: Institut für Experimentelle Physik VI: Lehrstuhl Angewandte Festkörperphysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/383065199?language=en
• 关键词: Auger; recomination; self; assembled; quantum

The Auger-effect is a many-particle scattering effect and of great significance, for instance, in material analysis (Auger-spectroscopy) and in optoelectronic devices where nanoparticles are used as light emitters like the fluorescence medium in commercially available television screens. In such colloidal nanoparticles, the Auger-process is decisive for inefficiencies in the photon conversion process, as the energy gets dissipated non-radiatively. This leads to spectral wandering (shifts of the emission wavelength) and blinking (on- and off-switching of the luminescence) of the nanoparticles. In single self-organized quantum dots, the Auger-effect has been neglected so far. In the presented project, this Auger-effect will be studied in detail in order to a get a deeper understanding of this fundamental effect on a well-known model system of self-assembled quantum dots. For this purpose, various quantum dot structures will be grown, characterized by a range of methods and finally investigated via resonance fluorescence towards their Auger-characteristics. This will be done in close cooperation of two project leaders located at the Ruhr-Universität Bochum and the Universität Duisburg-Essen. Especially sample structures with quantum dots of different size and shape, having different tunnel-coupling to a charge reservoir and an additional super lattice for creation of sub-band states will be grown and measured by resonance fluorescence. Moreover, the influence of external magnetic- and internal electric field on the Auger-recombination rate will be studied. A detailed understanding of the Auger effect in self-organized quantum dots could reveal external or internal tuning knobs to suppress the Auger-recombination and create structures for quantum-light emitters with high intensity and narrow linewidth.

俄歇效应是一种多粒子散射效应，在材料分析（俄歇光谱学）和光电器件中具有重要意义，其中纳米粒子用作光发射体，如市售电视屏幕中的荧光介质。在这种胶体纳米颗粒中，俄歇过程对于光子转换过程中的低效率是决定性的，因为能量以非辐射方式耗散。这导致纳米颗粒的光谱漂移（发射波长的偏移）和闪烁（发光的开关）。在单个自组织量子点中，俄歇效应一直被忽略。在本项目中，将详细研究这种Auger效应，以便更深入地了解这种基本效应对自组装量子点的已知模型系统的影响。为此，将生长各种量子点结构，通过一系列方法表征，并最终通过共振荧光对其俄歇特性进行研究。这将在位于鲁尔大学波鸿和杜伊斯堡-埃森大学的两个项目负责人的密切合作下完成。特别是具有不同尺寸和形状的量子点的样品结构，具有与电荷库的不同隧道耦合和用于创建子带态的额外超晶格，将通过共振荧光生长和测量。此外，外部磁场和内部电场的俄歇复合率的影响将进行研究。对自组织量子点中俄歇效应的详细理解可以揭示外部或内部调谐旋钮来抑制俄歇复合，并创建具有高强度和窄线宽的量子光发射器的结构。