| 摘要: | 隨著科技的進步，白光發光二極體(white light-emitting diodes, WLEDs)逐漸取代白熾燈和螢光燈，成為固態照明和背光顯示器的主流選擇。量子點(quantum dots, QDs)憑藉其獨特的發光特性，已經超越傳統的螢光粉，成為新一代發光材料的代表。在所有量子點種類中，磷化銦(indium phosphide, InP)量子點因其環境友善性和相比於傳統II-VI半導體的穩定性及共價特性而受到特別關注。
本研究中，通過在InP量子點合成過程中加入鹵化鋅前驅物，成功合成了銦鋅磷(InZnP)合金奈米晶體，以改善其光學特性。鋅的添加促進了InZnP合金奈米晶體的形成，與純InP相比，其具有更寬的能隙能量。X射線吸收光譜(X-ray absorption spectroscopy , XAS)的結果證實了合金具有顯著的富鋅表面層，這一特性不僅使InZnP核心和硫化鋅(zinc sulfide, ZnS)殼層間的晶格常數過渡更為平滑，而且促進了ZnS殼層的生長。與InP核心相比，InZnP合金結構減輕了InP的表面缺陷態，從而顯著提升量子效率。此外，本研究突顯不同鹵化鋅前驅物對量子點光學特性的影響。特別是，使用高反應性氯化鋅合成的量子點核心展現了增強的Zn-O鍵結，能有效減少InP 量子點的固有表面缺陷。殼層形成後，量子點的光學特性得到了明顯提升，進一步凸顯在量子點合成中選擇合適前驅物的重要性，並且強調前驅物的選擇對量子點光學性質方面的關鍵作用，以及對於最終元件效能的影響。
在照明應用中，CS-Cl/SSN-LED元件顯示出極佳的演色性(color rendering index, CRI)為83。在顯示器應用方面，CS-Br/KSF-LED元件達到了110 % NTSC (National Television System Committee)的色域覆蓋率，使其成為未來顯示技術的領先競爭者。總體而言，此研究成果不僅彰顯了InZnP/ZnS量子點在推動LED技術發展方面的巨大潛力，也在提升發光效率和色彩演色方面取得了顯著的進展。
;With the advancement of technology, white light-emitting diodes (WLEDs) have increasingly replaced incandescent and fluorescent lamps, becoming widely used in solid-state lighting and backlight displays. Quantum dots (QDs) have emerged as a new generation of luminescent materials, replacing traditional phosphors owing to their unique luminescent properties. Among them, indium phosphide (InP) QDs are notable not only for their environmental sustainability but also for their superior covalent properties and better stability compared to conventional II-VI semiconductors, such as cadmium-based ones.
In this study, zinc halide precursors were incorporated during the synthesis of InP QDs to generate InZnP alloy nanocrystals, aimed at improving their optical properties. The addition of zinc promotes the formation of InZnP alloy nanocrystals, which possess a wider band gap energy compared to pure InP. X-ray absorption spectroscopy revealed that the alloy displays a significant zinc-rich surface layer, leading to a smoother lattice parameter transition at the interface between the InZnP core and the zinc sulfide (ZnS) shell. This change facilitates the growth of the ZnS shell. The InZnP alloy structure, compared with the InP core, alleviates InP defect states, thereby significantly improving the quantum yield (QY) of the InZnP/ZnS QDs. Additionally, this study highlights the substantial impact of different zinc halide precursors on the optical properties of QDs. Specifically, QDs synthesized with highly reactive zinc chloride exhibit increased Zn-O bonds, effectively reducing the inherent surface defects of InP QDs. After the formation of the shell, the optical properties of the QDs were significantly enhanced. This underscores the importance of selecting appropriate precursors in the synthesis of QDs, highlighting the pivotal role of precursor choice in influencing the optical characteristics of the QDs, and its decisive impact on the optical performance of the final product.
For lighting applications, the CS-Cl/SSN-LED device has been innovatively designed, boasting an impressive color rendering index (CRI) of 83. In display applications, the CS-Br/KSF-LED device achieves an exceptional 110% coverage of the National Television System Committee (NTSC) color gamut, positioning it as a leading contender for future display technologies. Overall, these findings underscore the potential of InZnP/ZnS QDs in advancing LED technologies, with notable improvements in photoluminescence efficiency and color rendering capabilities. |
