聚3-甲基噻吩修饰硫化物量子点连接纳米结构TiO2膜的光电化学研究

采用原位化学法在纳米结构TiO₂膜上制备了量子点CdS, PbS (Q-CdS, Q-PbS), 并用电化学方法在TiO₂/Q-CdS, TiO₂/Q-PbS表面聚合3-甲基噻吩poly(3-Methylthiophene, PMeT)]. 用光电化学方法研究了PMeT修饰Q-CdS, Q-PbS连接TiO₂纳米结构膜, 实验结果表明, PMeT和Q-CdS, Q-PbS单独修饰纳米结构TiO₂电极和PMeT修饰Q-CdS, Q-PbS连接纳米结构TiO₂电极的光电流产生的起始波长都向长波方向移动; 一定条件下在可见光区光电转换效率均较纳米结构TiO₂的光电转换效率有明显的提高; 聚3-甲基噻吩(PMeT)与Q-CdS, Q-PbS连接的纳米结构TiO₂之间存在p-n异质结. 在一定条件下p-n异质结的存在有利于光生电子/空穴的分离, 在本文实验条件下PMeT修饰Q-CdS, Q-PbS连接纳米结构TiO₂电极最高的单色光的光电转换效率分别为11%和7%.

Photoelectrochemical Study of Poly(3-methylthiophene) Modified Composite Sulfide Anchored Nanostructured TiO2 Film

The Q-CdS, Q-PbS quantum dot were formed in situ on the nanocrystalline TiO2 electrode using chemical bath deposition techniques and the poly(3-methylthiophene) (PMeT) was prepared with electro- chemical method on TiO2/Q-CdS (Q-PbS) film. The photoelectrochemical properties of PMeT modified Q-CdS, Q-PbS anchored nanostructured TiO2 film were studied by photoelectruchemical method. The re- sults indicated that PMeT, Q-CdS and Q-PbS modified TiO2 film and PMeT modified Q-CdS, Q-PbS an- chored nanostructured TiO2 film produced photocurrent in the longer wavelength region under certain con- dition. In infrared light region, the conversion efficiency of light to electricity for the composite semicon- ductor nanoporous films was greatly improved compared with that of the nanostructured TiO2. The experi- ment result showed that the p-n heterojunction existed in the nanostructure TiO2/Q-CdS (Q-PbS)/PMeT film electrode, which favored the separation of electron/hole pairs generated by photoexcitation. It cound be seen that the maximum value of incident photon to current conversion of efficiency (IPCE) for PMeT modified Q-CdS, Q-PbS anchored nanostructured TiO2 film was 11% and 7% respectively.