TiO2表面氧空位对Rup2P/TiO2/ITO薄膜电极光致电荷转移的影响

采用改性的TiCl4水解法制备出三种不同表面性质的TiO2-X(X=5,10,20,X表示加入NaOH的浓度,单位为mo·lL-1)样品.利用(1,10-邻菲咯啉)2-2-(2-吡啶基)苯咪唑钌混配配合物(Rup2P)作为敏化剂,制备出Rup2P/TiO2-5/ITO(铟锡金属氧化物)、Rup2P/TiO2-10/ITO和Rup2P/TiO2-20/ITO表面敏化薄膜电极.测试结果表明三种薄膜电极的光电转换效率Rup2P/TiO2-10/ITO最高,Rup2P/TiO2-20/ITO次之,Rup2P/TiO2-5/ITO最低.利用吸收光谱、表面光电压(SP)谱、荧光光谱和表面光电流作用谱等分析了Rup2P和三种TiO2的能带结构和表面性质;利用光致循环伏安和表面光电流作用谱研究了三种Rup2P/TiO2-X/ITO薄膜电极的光致界面电荷转移过程.结果表明,在光致界面电荷转移过程中,TiO2层表面氧空位对Rup2P/TiO2-X/ITO薄膜电极光致电荷转移产生重要影响.并进一步讨论了Rup2P/TiO2-X/ITO薄膜电极的光电流产生机理.

Infection of Oxygen Vacancy at the TiO2 Surface for Film Electrode Rup2P/TiO2/ITO Photo-Induced Charge Transfer

The surface properties of TiO2 -X(X=5,10,20,X=NaOH](in mol·L -1 ))samples prepared by modification of hydrolyzed TiCl4 were studied.The surface-sensitized Ru(phen)2 (PIBH)(Rup2P)(phen= phenanthroline,PIBH=pyridyl benzimidazole hybrid)film electrodes Rup2 P/TiO2-5/ITO(indium tin oxide), Rup2P/TiO2-10/ITO,and Rup2P/TiO2-20/ITO were prepared.Among the three films,the photovoltaic properties of Rup 2P/TiO2-10/ITO were the best and those of Rup2 P/TiO2-5/ITO were the worst.The band structures,and properties on the surfaces of Rup2 P and the three TiO2 samples were analyzed using absorption spectra,surface photovoltage spectra,photoluminescence spectra,and photocurrent action spectra.The photo-induced charge transfer process was studied by cyclic voltammetry under irradiation and photocurrent action spectra.The results revealed the oxygen vacancy at the TiO2 surface was very important for the photo-induced charge transfer process of Rup2P/TiO2-X/ITO.The photocurrent mechanism of Rup2 P/TiO2-X/ITO is discussed.