长激子寿命有机染料的设计、合成与性能研究

In view of the national key strategic demand on energy, this project will aim to enhance the power conversion efficiency of organic dye-sensitized solar cells. Owing to the basic physical problem that organic dyes featuring wide spectrum response display a short lifetime of excited state, which limits the enhancement of devices performance for organic dye-sensitized solar cells, this project intends to achieve the preparation of new organic dyes characteristics of long lifetime of excited state, based on the design with quantum chemistry calculation. In addition, we will clarify the essence of pathways and rates of energy transfer and charge transfer such as dye structures related apparent exciton lifetime, electron injection, hole injection, charge recombination etc., which affect the power conversion efficiency, by employing wide-timescale temporal spectroscopic and high-speed/high-sensitive time-resolved photoelectric techniques. Furthermore, we will deploy the obtained fundamental knowledge to realize the rational design of key materials and devices engineering, fabricating high-performance dye-sensitized solar cells based upon organic photosensitizers, thereby providing a candidate solution for low-cost clean energy.

围绕国家能源重大战略需求，本项目将以提高有机染料敏化太阳电池光电转化效率为目标。针对目前该器件所用宽光谱有机染料的激发态寿命较短这一限制器件效率提升的基本物理问题，本项目拟基于量子化学计算设计，实现新型长激子寿命有机染料的制备，并利用宽时域时间分辨光谱和高速高灵敏时间分辨光电测量技术，探索材料化学结构依赖的表观激子寿命、电子注入、空穴注入及电荷复合等影响器件功率转换效率的能量转移与电荷转移路径与速率的本质。在此基础上，通过进一步材料的理性设计与器件工程，制备出高性能有机染料敏化太阳电池，从而提供一种低成本清洁能源的备选方案。

基于传统窄能隙有机染料的染料敏化太阳电池普遍具有较低的外量子产率。其原因主要是由于有机染料激子寿命短导致界面电子注入产率的降低。通过化学合成来实现“窄能隙有机染料的激发态控制”是当前器件效率突破的一个制高点。通过项目的实施，我们改善时间分辨光谱测试系统的灵敏度，为新型太阳电池激发态物理及界面电荷传递动力学的研究提供了有力的研究手段。将宽带荧光上转换、宽带瞬态吸收两种超快光谱技术结合，并提出了半导体纳晶表面“激发态多步弛豫、多态电子注入”的物理模型。明晰了开发长激子寿命有机染料的必要性。提出了“减小给受体电子关联、增强分子内电荷转移”的概念，制备出系列非氰基丙烯酸类电子受体，打破了氰基丙烯酸类有机染料激发态寿命受限于能隙规则这一传统认知。以较精确的材料计算为基础，设计并制备出系列具有自主知识产权、刚性电子骨架、能隙递变的苝基多环芳烃非氰基丙烯酸有机染料，在激发态控制、高效器件方面取得重要进展。获8个授权中国发明专利，发表SCI论文15篇（IF>7的9篇），相关研究被Chemical & Engineering News等多次正面评述。