表面敏化TiO_2基复合薄膜的能带结构与光致电荷转移的研究  

Band Structure and Photo-induced Charge Transfer in Surface-sensitized TiO_2-based Composite Films

作　　者：董江舟[1] 赵峻岩[1] 巢晖[2] 曹亚安[1] 

机构地区：[1]南开大学物理学院,天津300071 [2]中山大学化学与化学工程学院,广州510275

出　　处：《化学学报》2011年第23期2781-2786,共6页Acta Chimica Sinica

基　　金：国家自然科学基金(Nos.50872056;51072082;21173121)资助项目

摘　　要：采用离子束溅射方法制备出TiO2/ITO,Zr4+掺杂的TiO2(TiO2-Zr)/ITO和ZrO2/TiO2/ITO复合薄膜.利用表面敏化方法制备出(1,10-邻菲咯啉)2(3,4,5-三氟苯基)咪唑并[5,6-f]邻菲咯啉钌混配配合物[Rup2O](p=1,10-邻菲咯啉,O=(3,4,5-三氟苯基)咪唑并[5,6-f]邻菲咯啉)/TiO2/ITO,Rup2O/TiO2-Zr/ITO和Rup2O/ZrO2/TiO2/ITO表面敏化TiO2基复合薄膜.表面光电压谱(SPS)表明,表面敏化TiO2基复合薄膜在400～600和350 nm产生的SPS响应峰的峰高比与TiO2基复合薄膜的结构密切相关.利用电场诱导表面光电压谱(EFISPS)确定了复合薄膜的能带结构,其结果分析表明,400～600 nm的SPS响应峰主要源于Rup2O分子的中心离子Ru 4d能级到配体邻菲咯啉π1*和配体咪唑并邻菲咯啉π2*跃迁;TiO2禁带内Zr4+掺杂能级的存在减小了光生载流子的复合,增加导带光生电子的数量;ZrO2/TiO2异质结构的存在有利于光生电子向ITO表面的转移,从而导致400～600 nm和350 nm SPS响应峰的峰高比的增加,意味着光致电荷转移效率的提高.The films of TiO2/ITO,ZrO2/ITO,TiO2-Zr/ITO and TiO2/ZrO2/ITO were prepared by ion-beam sputtering,all of which were also surface-sensitized with Rup2O（p=1,10-phenanthroline,O=（3,4,5-tri-fluorophenyl） imidazo phenanthroline） by using the rolling coat method.The physical parameters and energy levels of TiO2-based and Rup2O modified TiO2-based films were ascertained by SPS and EFISPS.Because of the electron transitions between Ru 4d level and ligand levels（1＊ and 2＊）,there were SPS peaks generated in Rup2O modified films in the spectral wavelength range from 400 nm to 600 nm.The SPS intensity ratios between each of the SPS peak at 400～600 nm and that at 350 nm were different for different energy levels in the TiO2-based films.The existence of Zr4＋ doping level in TiO2-Zr forbidden bands makes the decrease of the recombination of photo-induced carriers while leads to the increase of the number of photo-induced electrons.Moreover,the heterogeneous structure in TiO2/ZrO2 is beneficial to the electron transfer to surface of ITO,which can enhance the SPS response and photo-electron transformation efficiency.

关 键 词：Rup2O 表面敏化 TiO2-Zr/ITO ZrO2/TiO2/ITO 光致电荷转移 

分 类 号：TM914.4[电气工程—电力电子与电力传动] O484[理学—固体物理]