基于单相双发射量子点的新型白光LED关键技术及相关机理研究

量子点材料具有尺寸依赖的光电学性质，较高的荧光量子效率和光化学稳定性，在新型固态照明LED领域具有极大的应用前景，成为目前新型LED发光材料的研究热点。量子点LED由于发光性能良好、使用寿命长，有望逐步取代传统照明电器成为新的“绿色”发光光源。本项目利用以能带工程为手段的量子点材料新型合成方法，即将核壳包覆、掺杂与合金化技术相结合，以与尺寸效应不一样的新途径来调节量子点材料的电子能级结构，从而获得具有与原量子点不一样的独特性质的单相双发射量子点新材料；在此基础上，进行新型量子点白光LED器件的组装，实现高质量的白光输出，具有较强的现实应用价值。同时，我们还深入研究核壳结构量子点的生长机理；探索掺杂和合金化对量子点电子能级结构的影响规律，确定相关的量子点发光机理和双发射竞争机制，为基于单相双发射量子点的新型高质量白光LED在未来的显示和照明领域扮演重要角色提供理论和技术基础。

Quantum dots (QDs) are bandgap-tunable materials by the size, and as a result, their fluorescence characteristics can also be varied. QDs have several optical merits, such as a narrow and symmetric emission spectrum and outstanding photochemical stability. For this reason, QDs have found many applications in light-emitting diodes (LEDs). The band structure of QDs can be controlled by shell coating, doping and alloying to obtain a series of dual emitting QDs. A white LED (WLED) lamp can be fabricated using a commercial blue-LED chip combined with the QDs phosphors as color converters. As-fabricated WLED showed improved color rendering properties, compared to commercial ones. These results indicate that these single-phase QDs phosphors are promising as versatile light-emitting materials for solid-state lighting applications, because of the flexibly tunable dual emission position in the Vis-to-NIR region. In addition, the formation mechanism of the core-shell structure and the emission mechanism of the doped and alloyed QDs are studied.