基于掺杂量子点的量子点单颗粒荧光闪烁机理研究

项目名称： 基于掺杂量子点的量子点单颗粒荧光闪烁机理研究

项目编号： No.21303159

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 秦海燕

作者单位： 浙江大学

项目金额： 25万元

中文摘要： 荧光闪烁现象普遍存在于各种荧光物质中，并限制了它们在单分子示踪和单光子光源等方面的应用。目前仅有少数几种非闪烁量子点被报道，而荧光闪烁的物理机理仍在争论中。本项目拟通过研究掺杂量子点单颗粒的荧光闪烁行为，揭示荧光闪烁现象背后的物理机理，建立理论模型，指导设计与合成非闪烁量子点。锰掺杂量子点的荧光性质具有良好的温度稳定性，且对表面配体不敏感，是研究荧光闪烁中非辐射复合过程的理想模型。锰掺杂量子点使用成核掺杂方法合成，并在表面包覆上壳层以增加其稳定性。利用荧光显微成像系统，结合脉冲激光与单光子计数技术，观测量子点单颗粒的荧光闪烁现象和测量单颗粒荧光寿命。通过统计和分析掺杂浓度、掺杂空间位置、表面配体、尺寸以及温度等参数对其荧光闪烁和寿命的影响，建立荧光闪烁的机理模型。在该理论模型的指导下，总结出抑制量子点荧光闪烁的普适策略，最终设计和合成非闪烁掺杂量子点，并推广到其它类型量子点体系中。

中文关键词： 掺杂量子点；量子点单颗粒；荧光闪烁；热载流子电离；非闪烁量子点

英文摘要： Fluorescence blinking is a common phenomenon in various fluorescent substances and limits their applications in many fields, such as single molecular tracking and single photon sources. Only a few types of nonblinking quantum dots have been reported and the physical mechanism behind fluorescence blinking is still in debate so far. Here we propose to study the fluorescence blinking behavior of single doped quantum dots and reveal the physical mechanism behind. Nonblinking quantum dots would be rationally designed and synthesized according to the theoretical model. The fluorescence properties of manganese-doped quantum dots are independent to temperature and surface ligands. Therefore, they are an ideal model for the study of nonradiative recombination process in fluorescence blinking. The manganese-doped quantum dots are fabricated using a nucleation-doping method and coating with an outer layer to enhance their stability. Fluorescence microscope imaging systems would be built up to observe the fluorescence blinking for single quantum dots. Accompanied with a pulse laser and a single-photon counting system, the fluorescence decay for each single quantum dot could be measured. A detailed study for the blinking behavior of single quantum dots affected by doping concentration and position, surface ligands, particel

英文关键词： Doped Quantum Dots；Single Quantum Dots；Fluorescence Blinking；Hot-carrier Ionization；Nonblinking Quantum Dots