多枝分级TiO2纳米线阵列的制备及其在量子点敏化太阳能电池中的应用研究

The multi-branched hierarchical TiO2 nanowire arrays will have important application in the field of photoelectrochemical solar cell since its large active surface area, high charge separation efficiency and excellent charge transport properties. This study is to use a simple wet chemical synthesis method to prepare a multi-branched hierarchical TiO2 nanowire array, and then assemble semiconductor quantum dots on the surface of nanowires to serve as light absorption layer in the quantum dot-sensitized solar cell. In this system, we want to increase the light adsorption by the multi-branched hierarchial configurations of TiO2 nanowire array, and modulate the charge separation and transport by nanowires combine with the II-type heterojunction between TiO2 and semiconductor quantum dots, since the II-type heterojunction will promote charge separation and the one-dimensional crystalline nanostructure will provide a direct conduction pathway for the rapid transport of photogenerated electrons. The preparation method of multi-branched hierarchical TiO2 nanowire array will be researched. And the effects of this complex hierarchical strcuture, the charge transfer of the heterojunction interface, and the thickness and composition of the semiconductor quantum dots light absorption layer for the performance of the solar cell device will also be studied detailed. Through the structure design for the photoelectrode materials, we want to get a dot-sensitized solar cell with higher photoelectric conversion efficiency.

具备大活性表面积、高电荷分离效率和优异的电荷输运性质的多枝分级TiO2纳米线阵列在光电化学太阳能转化与利用领域有重要应用。本研究就是要利用简单的液相化学合成方法制备多枝分级的TiO2纳米线阵列，并在纳米线表面组装与TiO2纳米线能带匹配的半导体量子点光吸收层，构建量子点敏化太阳能电池。利用一维纳米线多枝分级结构增大材料对光的吸收；利用一维纳米线结构独特的导电通路及TiO2纳米线与半导体量子点间II型异质结的构建调制电荷的分离与输运。研究多枝分级TiO2纳米线阵列的制备方法及这种复杂分级结构、异质界面的电荷传输、半导体量子点光吸收层厚度和组成等对太阳能电池性能的影响。制备具有高光电转换效率的量子点敏化太阳能电池材料。

光阳极的组成、微结构、表/界面修饰、以及界面电荷转移机制研究一直是光电化学电池领域的研究热点。本研究主要从TiO2一维纳米线阵列及其分级结构的调控生长、太阳能电池器件的结构组成优化设计及其光电化学电池特性研究、以及电池器件表/界面修饰及电荷传输动力学方面开展了研究工作，均取得重要研究进展。获得了简单液相合成方法下一维TiO2纳米线及其分级结构的长度、密度及分支密集度可控的生长技术；设计了TiO2金红石纳米线/锐钛矿纳米粒子、TiO2纳米线/纳米粒子/球形空腔散射层多级复合结构光阳极，研究了不同光阳极组成及微结构对电池光利用率及器件性能的影响规律；组装了不同半导体/量子点光吸收层（CdS、Sb2S3、钙钛矿、CZTS）敏化的一维纳米线/分级结构电池器件，并研究了其光电化学特性；同时，对TiO2光阳极进行了氢处理、TiCl4处理、以及界面阻挡层修饰，深入研究了不同表界面处理对电极光电化学性能的影响规律。本研究工作对量子点敏化等光电化学太阳能电池器件研究领域具有重要的参考价值及指导意义。研究期间共发表SCI检索论文7篇，超学科平均影响因子论文5篇，在投论文2篇。参加国内外会议10余人次。培养研究生9名。