8-羟基喹啉铁配合物对锐钛矿型TiO2(101)表面的敏化机理

Sensitization Mechanism of Tris(8-hydroxyquinoline)iron (III) on TiO_2 Anatase (101) Surface

用密度泛函理论和DMol3程序包对锐钛矿型TiO2(101)表面复合三(8-羟基喹啉-5-羧酸)铁的敏化机理进行了研究.计算结果表明,该染料敏化剂经式结构的HOMO(最高占据分子轨道)-LUMO(最低未占据分子轨道)能隙非常小,很容易受到激发;TiO2纳米晶吸附染料后,HOMO、LUMO和费米能级都升高,导致吸附染料后开路电压VOC升高.并进一步探讨了三(8-羟基喹啉-5-羧酸)铁在TiO2(101)表面复合过程及作用机理.

Density functional theory （DFT） in periodic DMol3 program was employed to investigate the sensitization mechanism of tris（8-hydroxyquinoline-5-carboxylic acid）iron （III） on TiO2 anatase （101） surface. This sensitizer possesses a very small HOMO （highest occupied molecular orbital）-LUMO （lowest unoccupied molecular orbital） energy gap and this allows for easy electron excitation from the HOMO to the LUMO. As the nanocrystalline TiO2 adsorbs the sensitizer, the energy of the HOMO level, the LUMO and Fermi level increase. These changes lead to an enhancement of the open-circuit photovoltage （V∝） in dye-sensitized TiO2 solar cells. In addition, we theoretically determined the sensitization mechanism of tris（8-hydroxyquinoline-5-carboxylic acid）iron （III） dyes that are attached by carboxylic acid anchor groups to TiO2 anatase （101） surface.