发光二极管（light-emitting diodes, LED）可高效地将电能转化为光能，在现代社会具有广泛的用途，因其具有高效节能、绿色环保、体积小巧、快速相应、色彩丰富等优点，如今广泛应用于显示领域。目前，我国的高清显示技术目前正处于快速发展阶段，受益于技术进步和市场需求增长，高清显示技术不断创新。显示屏分辨率更高、色彩范围更广、色彩准确性更强是人们一直以来的技术追求，研发满足Rec.2020色彩标准的显示屏更是未来显示产业的发展方向。因此，发展高色纯度、窄谱带的发光材料具有重要的现实意义。

深红光发射二极管（DR-LEDs，波长>660 nm）以其高色彩纯度和窄带宽发射，在全彩显示和固态照明应用中显示出良好的潜力。目前，DR-LEDs主要依赖于传统发射体，如有机材料以及基于重金属的量子点（QDs）和钙钛矿。然而，有机材料的合成复杂，色彩纯度较差（半峰全宽超过40 nm），而量子点和钙钛矿则存在严重的毒性问题。荧光碳量子点（carbon quantum dots, CQDs）是一种新兴的尺寸小于10 nm的零维碳纳米材料，具有环境友好、成本低、生物相容性好、表面易功能化等许多突出的优点，这些特性使得荧光碳量子点在生物成像、离子检测、催化和光电器件等领域有巨大的应用潜能。然而，目前大多数报道的碳量子点大多具有大半峰全宽（FWHM>80 nm）的宽带发射光谱，色纯度较差，这对于高效的宽色域显示器是非常不利的。因此，寻找合适的前驱体及合成方法，合成高色纯度、窄谱带碳量子点，并探究其化学结构与发光性能之间的构效关系具有重要的现实意义。在本论文中，我们从便宜易得的绿色植物出发合成了高效且色彩纯度高的深红碳量子点（CQDs），其半峰全宽记录为22 nm，为CQDs在高分辨率发光显示技术中的应用打开了新的可能性。

Light-emitting diodes (LEDs) competently transform electrical energy into light energy and have a wide range of applications in modern society. They are valued for their energy efficiency, environmental friendliness, compact size, rapid response, and rich color gamut. Currently, high-definition display technology in China is undergoing rapid development, benefiting from technological advancements and increased market demand. Continuous innovation in high-definition display technology is aimed at achieving higher screen resolutions, wider color gamuts, and stronger color accuracy, with the development of displays meeting the Rec.2020 color standard being a future direction for the display industry. Therefore, the development of high-purity, narrow-band emitting materials is of great practical significance.

Deep red light-emitting diodes (DR-LEDs, wavelength >660 nm) exhibit promising potential in full-color displays and solid-state lighting applications due to their high color purity and narrow bandwidth emission. Currently, DR-LEDs primarily rely on traditional emitters such as organic materials, heavy metal-based quantum dots (QDs), and perovskites. However, organic materials have complex synthesis processes and poor color purity (with full width at half maximum exceeding 40 nm), while quantum dots and perovskites suffer from serious toxicity issues. Fluorescent carbon quantum dots (CQDs) are a novel zero-dimensional carbon nanomaterial with dimensions smaller than 10 nm, featuring environmental friendliness, low cost, good biocompatibility, and easy surface functionalization, among other outstanding advantages. These characteristics make fluorescent carbon quantum dots highly promising for applications in bioimaging, ion detection, catalysis, optoelectronic devices, and more. However, most reported carbon quantum dots currently exhibit broad emission spectra with large full width at half maximum (FWHM >80 nm), resulting in poor color purity, which is unfavorable for efficient wide-color-gamut displays. Therefore, it is of great practical significance to explore suitable precursors and synthesis methods for synthesizing high-purity, narrow-band carbon quantum dots, and to investigate the structure-performance relationship between their chemical structure and luminescent properties. In this study, we synthesized highly efficient and high-purity deep red carbon quantum dots (CQDs) from readily available green plants, with a record FWHM of 22 nm, opening up new possibilities for the application of CQDs in high-resolution emissive display technology.