近红外稀土上转换有机光敏染料的设计、制备与发光增强研究

Dyes sensitized rare-earth upconversion nanoparticles (UCNPs) can expand the absorption of near-infrared solar energy to improve the upconversion efficiency, and have broad application prospects in the field of photocatalysis and photovoltaic devices. However, there are some deficiencies for photosensitive dyes, such as energy mismatch with UCNPs, and easy self-quenching of excited state on the surface of UCNPs. In this project, the structure of photosensitive dyes is taken as the point of view. Under the premise of adjusting the energy matching of dyes/UCNPs, we propose to use interface effect to improve the upconversion efficiency. On the one hand, the aggregation-induced emission group is utilized to inhibit the self-quenching effect of dyes. On the other hand, the molecular structure is optimized to modulate their aggregation and density onto UCNPs. The relationship between dye structure, interface effect and upconversion performance is systematically studied to master the modification method of dye structure and the regulation mechanism of upconversion properties, and to realize the controllable preparation of organic dye-sensitized UCNPs composites. The implementation of this project will provide a new research idea for organic dye-sensitized UCNPs composites, and provide new theoretical and experimental basis for the development of low-power upconversion materials with broadband near-infrared absorption, high upconversion efficiency and stability.

利用染料分子敏化稀土上转换纳米材料（UCNPs）可以拓展近红外太阳能的吸收，提高上转换效率，在光催化和光伏器件等领域具有广阔的应用前景。然而，现有光敏染料由于能量失配和界面激发态猝灭等因素限制弱光上转换效率提高。为此，本项目拟从染料分子结构出发，在调控染料/UCNPs能量匹配的前提下，一方面引入聚集诱导发光效应基团抑制染料复合时激发态自猝灭，另一方面通过分子结构优化调控染料在UCNPs表面的聚集结构和复合密度，利用界面效应提高上转换效率。通过系统研究染料结构、界面效应与上转换性能之间的关系，建立染料结构修饰方法，掌握上转换性能调控机制，实现染料敏化UCNPs复合材料可控制备。本项目的实施将为染料敏化UCNPs复合材料提供新的研究思路，为开发近红外宽谱带响应、高效、稳定的弱光上转换材料提供新的理论和实验依据。

染料敏化是提高稀土上转换纳米材料（UCNPs）发光的有效方法，然而染料在UCNPs表面的严重聚集导致上转换效率偏低，限制实际应用。本项目从染料分子出发，利用分子共轭性、聚集诱导发光效应基团，优化染料固定基团等结构调控方法，制备了一系列光敏染料。染料与UCNPs复合比提高了4倍，染料敏化上转换发光提高了135倍（785 nm，5 W/cm2）。利用静电控制效应，优化染料敏化UCNPs溶剂等介质调控方法，进一步将染料与UCNPs的复合比提高了2.5倍，上转换发光提高了7倍。系统研究了染料结构、界面效应与上转换性能之间的关系，建立了染料结构修饰方法，探索了染料与UCNPs的作用机制。在此基础上，积极开展了染料敏化上转换材料在防伪印刷领域的应用探索。本项目的实施为开发宽谱带响应、高效的近红外-转-可见光上转换材料提供了重要实验数据和理论依据。