摘要: 采用溶胶-凝胶法制备出 In 表面修饰的 TiO2 (TiO2-Inx%)纳米粒子, x%代表在 In 掺杂的 TiO2样品中 In 3+ 与 In 3+ 和 Ti 4+ 离子摩尔百分含量. 利用二(四丁基铵)顺式-双(异硫氰基)双(2,2ʹ-联吡啶-4,4ʹ-二羧酸)钌(II)(N719) 作为敏化剂, 制备出 N719/TiO2/FTO (氟掺杂锡氧化物)和 N719/TiO2-Inx%/FTO 染料敏化薄膜电极. 光电转换 效率实验表明, 在薄膜电极+0.5 mol •L-1 LiI+0.05 mol •L-1 I2 的三甲氧基丙腈(MPN)溶液+Pt 光电池体系中, N719/TiO2-Inx%/FTO 薄膜电极的光电转换效率均高于 N719/TiO2/FTO, 其中 N719/TiO2-In0.1%/FTO 的光电 转换效率比 N719/TiO2/FTO 提高了 20%. 利用 X 射线衍射(XRD)、 X 射线光电子能谱(XPS)、 漫反射吸收光谱 (DRS)、 荧光(PL)光谱和表面光电流作用谱确定了 TiO2-Inx%样品中 In 3+ 离子的存在方式和能带结构; 利用表面 光电流作用谱研究了 N719/TiO2-Inx%/FTO 薄膜电极的光致界面电荷转移过程. 结果表明, In 3+ 离子在 TiO2表面 形成 O-In-Cln (n=1, 2)物种, 该物种的表面态能级位于导带下 0.3 eV 处; 在光电流产生过程中, O-In-Cln (n=1, 2) 表面态能级有效地抑制了光生载流子在 TiO2-Inx%层的复合, 促进了阳极光电流的增加, 从而导致 N719/ TiO2-Inx%/FTO 薄膜电极的光电转化效率高于 N719/TiO2/FTO, 并进一步讨论了光致界面电荷转移的机理.

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 Rup2P/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 Rup2P/TiO2-10/ITO were the best and those of Rup2P/TiO2-5/ITO were the worst. The band structures, and properties on the surfaces of Rup2P 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 Rup2P/TiO2-X/ITO is discussed.

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