卟啉与氟硼二吡咯类染料共敏化太阳能电池研究

The organic dye sensitized solar cells (DSSCs) have be considered as one of the most effective way to make use of the solar energy. Studies on the porphyrin sensitizers have become one of the most active research area in the world. It is known that for a single dye sensitizer it is hard to have absorption in the whole solar spectrum which inhibits the further improvement of the light to electricity conversion efficiency (η) of DSSCs. One effective way to broaden the light absorption range of the sensitizer is to co-sensitized the TiO2 electrode with two or more dyes which have complementary absorption in the solar spectrum. In this project, novel porphyrin sensitizers and the complementary dyes will be designed and synthesized, and the improvement of the performance of DSSCs can realized via co-sensitization approach. The consensitization mechanism will be investigated. The complementary dyes will be based on the boron fluoro dipyrromethene (BODIPY) which is attached to a triaryl amine derivative. Thus, a hole transfer type dye sensitizer with excellent performance can be obtained, which will be mixed with our synthesized porphyrin dyes. When compared with single porphyrin or BODIPY sensitizer, the mixted dye sensitizers are expected to have broadened light absorption range and enhanced absorption coefficients. Furthermore, the new photoanode materials which are suitable for our newly developed cosensitizers will be prepared, such as mesoporous TiO2 materials which are good at absorbing sunlight, graphene-doped and rare earth-doped TiO2 materials which can facilitate electron transfer. Thus, the Jsc and Voc values can be improved which will lead to the enhancement of the final η. The success of the proposed project is expected to lead to a breakthrough in the area of DSSCs and can provide theoretical and technical support for the future developement of the organic solar cells.

有机敏化太阳能电池是太阳能利用的有效途径之一。卟啉光敏染料的研究成为世界上最活跃的课题之一。单一敏化染料很难实现全太阳光谱的吸收，限制了光电转换效率的进一步提高。通过将吸收光谱互补的两种或多种染料混合进行共敏化，是提高太阳光利用的有效途径。本项目设计并合成新型卟啉敏化染料及与其匹配的共敏化染料，通过共敏化方法实现总体光伏性能的提升。研究卟啉染料共敏化机理，在共敏化染料的选择上，将三芳胺化合物通过缩合连接到氟硼二吡咯化合物上，合成具有性能优良的空穴传输型染料作为新型共敏化染料，以期扩大染料对光的吸收范围和强度。同时制备与共敏化染料匹配的新型光阳极材料,如有利于染料吸收的介孔TiO2材料、有利于电子传输的石墨烯掺杂 TiO2材料、稀土元素掺杂TiO2材料,来提高短路电流和开路电压，达到提高光电转换效率的目的。可望在敏化染料太阳能电池领域有所突破，为有机太阳能电池的开发提供理论和技术支持。

太阳能利用是全球瞩目的战略性课题，卟啉光敏染料太阳能电池是研究低价、高效太阳能利用的最活跃的课题之一。 本项目设计并合成两类中位和β位卟啉敏化染料以及氟硼二吡咯敏化染料，研究了敏化染料结构与光电性能的关系及两类敏化染料的共敏化机理；研究了新型光阳极材料。此外对卟啉敏化染料进行了理论计算；对电解质进行了研究。获得卟啉染料及氟硼二吡咯共敏化染料的结构与光电性能关系的规律，揭示了卟啉染料与共敏化染料的共敏化机理。 .获得了敏化染料分子结构与光电性能的关系： （1）在卟啉中位引入正长的烷氧基链可抑制染料聚集，是提高电子注入效率和阻止电子复合的有效方法。（2）在卟啉环和锚定基团之间引入吸电子能力强的苯并喹喔啉和苯并噻二唑，具有更红的Q带吸收、更宽的IPCE峰和更好的光捕获效率、更高短路电流。（3）D-A-π-A结构的卟啉染料上噻吩桥上氟原子的引入以及锚定基团上引入氰基或延长π共轭有助于提高染料的光捕获能力。（4）三芳胺-BODIPY染料中，供电基团结构中苯环被锁定的三芳胺降低了其自由旋转造成的非辐射能量损失，更有利于电子供体到BODIPY核的电荷转移。具有更高荧光量子产率和更长荧光寿命的染料将会获得更优的光电性能。.揭示了共敏化机理，BODIPY染料与卟啉染料的共敏化，存在从卟啉染料到BODIPY染料的FRET能量转移，存在共敏化染料之间的相互抑制聚集作用，同时存在分子尺寸互补、共敏化TiO2薄膜光阳极上的染料分子更加无序、分子之间间隙变大。总的协同作用结果提高了光电流；比单个敏化染料光电转化效率提高了14.7%。共敏化是提高敏化染料光电性能的有效途径。.在国内外重要学术刊物Physical Chemistry Chemical Physics 、Journal of Materials Science、Nano Reasearch、RSC Advances、Journal of Power Sources、 Dyes and Pigments 等上发表标注基金委资助的论文31篇，其中26篇为第一标注。