FTO表面预处理对TiO_2纳米棒阵列的形貌及光电性能的影响

The Effects of Pretreatment on Morphologic and Electronic Performance of TiO_2 Nanorod Arrays in Quantum dot Sensitized Solar Cells

采用TiCl4水解法先对透明导电玻璃(FTO)进行表面预处理,形成一层薄的种子层,再用钛酸正四丁酯作为钛源在其上水热生长TiO2纳米棒阵列.用XRD和SEM表征了种子层和纳米棒阵列的晶型和微观形貌,用紫外-可见吸收光谱、电池的J-V曲线和阻抗谱对其光电性能进行了研究.发现纳米棒属于TiO2金红石相,种子层则是TiO2金红石相和锐钛矿相的混合相.不同浓度TiCl4溶液预处理过程对TiO2纳米棒阵列的形貌及光电性能都有明显影响.采用复合量子点敏化后组装成电池的效率先增大后减少,且在TiCl4溶液浓度为0.15M时电池效率最高,为1.51%,比没有进过预处理的电池高出30%.

We changed the preparation conditions of the seed layers and obtained electrodes with different morphologies. The morphology and crystal phase of the electrodes were investigated by scanning electron microscopy（SEM）and X-ray diffraction measurement （XRD）. Current density- voltage （J-V）and electrochemical impedance spectroscopy （EIS）measurements were performed to investigate the efficiencies and recombination pro- cesses of quantum dot-sensitized solar cells （QDSSCs）. The results showed that the introduction of seed layer to FTO substrates promoted heteroge- neous nucleation and increased the verticality and density of nanorods, and improved the cells＇ performance a lot. The highest efficiency of 1.51% was achieved, which is over 30% higher than that of the cell without a seed layer.