激光照明用煤基碳量子点固态荧光材料的结构和性质调控

High-efficient and low-cost white light semiconductor laser diode (LD) holds a great potential for solid illumination, of which the performance can be further improved by making use of solid fluorescent materials such as carbon quantum dots (CQDs) with tuned structure and properties. Coal-derived CQDs are one of the promising candidates as solid fluorescent materials to improve the performance of LD and reduce its cost. This proposal aims to address the controllable preparation of single CQDs with high quantum yield, high red-green-blue spectral composition and good stability by using coal and its derivatives as carbon source, and to explore the application potential of the CQDs in UV-chip based white LD with a focus on the structure-property-performance relationship. On the basis of our previous research on the successful synthesis of coal-derived CQDs by chemical oxidation, the structure and surface properties as well as fluorescent performances of CQDs will be tuned by grafting modification, doping or fabrication of nano-composites according to the strategies of physical and chemical surface treatment and heteroatom doping treatment. The formation and luminous mechanism of CQDs will be examined in detail. Fluorescence films will be constructed with functionalized CQDs as constituent element in order to establish the strategy for design and fabrication of solid CQDs fluorescent system with strong emission, high red-green-blue composition and good stability. The intrinsic relationship between materials/devices and their structures/properties will be explored in detail to reveal the dependence of photoelectric performance of LD on the composition of coal-derived carbon sources, CQDs structure and optical properties of fluorescence film. This will lead to a technology that is capable of producing solid CQDs fluorescence materials with excellent properties. This project will help to lay the solid foundation for the effective utilization of coal resources and the large-scale application of coal-derived CQDs in laser illumination in terms of both theory and technology support.

高效低成本的白光半导体激光器(LD)在照明领域具有潜在的应用前景，利用煤基固态发光碳量子点(CQDs)有望提高LD性能并降低其成本。本项目拟以煤及其衍生物为碳源，合成高荧光量子产率、红绿蓝光比重且稳定的近紫外激发白光LD用单一基质CQDs。在团队前期化学氧化法合成煤基CQDs的研究基础上，基于表面物理化学效应和杂原子掺杂效应之策略，采用接枝、掺杂或纳米复合化技术，调控CQDs结构和表面性质及发光性能，揭示其形成和发光机制；以功能化CQDs为组元构筑荧光薄膜，建立荧光特性强和红绿蓝比重高且稳定性好的固态CQDs荧光体系及性能调变的技术策略；基于材料和器件的结构与性能的本征关系，诠释煤基碳源组成、CQDs结构、荧光膜发光特性和LD光电性能之间的构效关系，建立构筑性能优良的CQDs固态荧光材料的平台性技术方法。项目的实施将为煤炭的高值利用及煤基CQDs在激光照明中的规模化应用提供理论和技术支撑。

为实现高效低成本白光半导体激光器（LD）的规模化和煤炭的高值利用，并解决固态碳量子点（CQDs）荧光猝灭的问题，本项目设计以煤及其衍生物为碳源合成多种煤基CQDs荧光材料，并将其作为荧光粉，制作得到高效白光发光二极管（LED）/LD器件；通过采用包埋法和化学键合法两种策略合成CQDs，实现其固态发光。.首先以煤沥青及其煤衍生物（有机小分子）为碳源，通过调节反应条件，优化设计并合成多种煤基CQDs，实现其尺寸、结构、性能的精确调控，获得具有荧光量子产率高（最高可达97.32%）、发光可调（从蓝到红）、带隙可调（3.17–2.94 eV）的功能化CQDs；同时，通过采用包埋法和化学键合法两种策略合成固态发光的CQDs。然后阐明了沥青种类、沥青的预处理条件、反应助剂种类、溶剂种类、碳源种类、反应参数对CQDs的结构和光学性能的影响规律。最后，将具有高热稳定性的功能化CQDs用作白光LED/LD器件的荧光粉，得到性能优良的白光LED/LD器件，其色坐标接近于理论白光（0.33，0.33），显色指数可达82–89，诠释了功能化CQDs结构、性质与白光LD光电性能之间的构效关系，最终获得一种用于LD器件的新型的荧光材料，为实现煤炭的高值利用及煤基CQDs在激光照明中的规模化应用提供了理论指导和技术支持。