用于p-型染料敏化太阳能电池的多酸基染料理论设计与性能研究

The dye-sensitized solar cells (DSSCs) have attracted considerable attention due to their low cost, green environmental protection, easy fabrication and so on. However, lower photoelectric conversion efficiency (PCE) of DSSCs in comparison with silicon solar cell, obstruct their wide application. In order to restrain the recombination between the hole in semiconductor and the electron in dye and improve the stability of dyes and the PCE of DSSCs, the polyoxometalates (POMs) as electron acceptor units will be introduced into dyes. The novel POM-based dyes will be designed based on the Lindqvist-, Anderson- and Keggin-type POMs and the organic segments. The effects of organic segments, the kinds and lengths of linkers on the adsorption spectra and photovoltaic performance will be investigated by theoretical calculations. In additon, aiming at revealing the charge transfer and transport process on the dye/semiconductor interface, the electron transfer process on the interface in DSSCs will be explored by using density functional theory and molecular dynamics simulation. The molecular design and performance study on the high efficiency POM-based dyes will be deeply performed. Meanwhile, based on the theoretical study, we will also synthesize new high-performance dyes and attempt to prepare the DSSC devices.

染料敏化太阳能电池因其成本低廉，绿色环保，易于大规模生产等优点引起理论与实验化学家的广泛关注。当前较低的光电转换效率制约了其广泛应用。本项目将多酸作为拉电子基团引入到染料中，增强染料的稳定性，拓宽光吸收范围，抑制半导体中的空穴和染料中的电子复合，以提高光电转换效率。以Lindqvist，Anderson和Keggin型多酸结构为基础，向其引入合适的有机配体，通过理论计算研究不同的有机配体、连接桥的种类和长度对提高空穴和电子的分离效率以及光伏性能的影响规律。采用密度泛函理论结合动力学模拟方法探索多酸基染料与半导体界面处的电子转移过程。深入进行高效多酸型染料的分子设计及性能研究，并以理论研究为依据，定向合成多酸基染料，尝试染料敏化太阳能电池器件制备。

染料敏化太阳能电池(DSSC)因其低成本、高效率、制造工艺简单等优点备受关注。染料敏化剂是DSSC的重要组成部分，其性能优劣直接影响电池的光电转换效率和光吸收效率。多酸结构稳定，具有优异的光电性质和较强的吸电子能力，可与有机基团键连形成具有良好光吸收性质的有机-无机杂化衍生物。依据实验合成的Lindqvist型和Keggin型多酸基有机-无机杂化衍生物，通过改变/修饰电子给体或者π共轭桥设计了一系列用于DSSC的光敏染料。采用密度泛函理论(DFT)和含时DFT(TDDFT)方法研究其电子结构，吸收光谱和电荷转移情况，筛选出性能优异的光敏染料。研究发现，增强电子给体的给电子能力，提高π共轭桥的离域性或者构建双D-A-π-A结构，有助于提高光敏染料的光伏性能。通过本项目的研究，建立了多酸基光敏染料的结构和性能关系，为实验合成提供重要信息。