Tan Shuxin, Zhai Jin, Fang Hongjun, Jiu Tonggang, Ge Jun, Li Yuliang, Jiang Lei, Zhu Daoben
Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing.
Chemistry. 2005 Oct 21;11(21):6272-6. doi: 10.1002/chem.200500425.
Novel carboxylated oligothiophenes with different thiophene units were designed and synthesized as photosensitizers in dye-sensitized solar cells (DSSCs) for efficient opto-electric materials. The introduction of -COOH into thiophene molecules can lead to a red shift of UV-visible absorption, increase light-harvesting efficiency, and enhance photoinduced charge transport by forming efficient covalent bonds to the substrate surface. A red shift of the absorption spectrum of oligothiophene is also achieved by the increase in the number of thiophene units. The DSSCs based on the oligomers have excellent photovoltaic performances. Under 100 mW cm(-2) irradiation a short-circuit current of 10.57 mA cm(-2) and an overall energy conversion efficiency of 3.36 % is achieved when pentathiophene dicarboxylated acid was used as a sensitizer. The incident photo-to-current conversion efficiency (IPCE) has a maximum as high as 80 %. In addition, photovoltage and photocurrent transients show that slow charge recombination in DSSCs is important for efficient charge separation and excellent photoelectric conversion properties of the oligomers. These initial and promising results suggest that carboxylated oligothiophenes are efficient photosensitizers.
设计并合成了具有不同噻吩单元的新型羧基化低聚噻吩，作为染料敏化太阳能电池（DSSC）中的光敏剂，用于制备高效光电材料。将-COOH引入噻吩分子可导致紫外-可见吸收光谱发生红移，提高光捕获效率，并通过与基底表面形成有效的共价键来增强光生电荷传输。低聚噻吩吸收光谱的红移也可通过增加噻吩单元的数量来实现。基于这些低聚物的DSSC具有优异的光伏性能。当使用五噻吩二羧酸作为敏化剂时，在100 mW cm(-2)的光照下，短路电流为10.57 mA cm(-2)，总能量转换效率为3.36%。入射光电流转换效率（IPCE）最高可达80%。此外，光电压和光电流瞬态表明，DSSC中缓慢的电荷复合对于低聚物的有效电荷分离和优异的光电转换性能很重要。这些初步且有前景的结果表明羧基化低聚噻吩是高效的光敏剂。
