CdS修饰低密度TiO2纳米棒阵列复合膜的制备及光电性能

为了提高CdS光敏层在TiO₂一维纳米棒阵列中的填充率，在TiO₂种子层的基础上，采用水热法于FTO导电玻璃表面生长了棒长较短、棒间距较大的低密度TiO₂一维纳米棒阵列膜，通过化学浴沉积在TiO₂纳米棒表面包覆CdS种子层，以此为基底采用水热法于TiO₂一维纳米阵列中生长CdS光敏层。采用SEM，XRD及紫外-可见吸收光谱对不同CdS水热生长时间的TiO₂/CdS复合膜结构进行了表征，并对其光电性能进行了研究。结果表明，低密度TiO₂纳米棒阵列有利于CdS生长液在阵列中渗入形成完全包覆的CdS种子层，CdS光敏层通过水热过程在整个TiO₂纳米棒表面均匀生长，逐渐形成CdS对TiO₂纳米棒阵列的完全填充和包覆，并在阵列顶端形成由CdS纳米短棒组成的花状修饰层；CdS的修饰将TiO₂一维纳米阵列膜的光吸收拓展至可见光区，水热生长7 h所得到的TiO₂/CdS复合膜具有最高光电流。所制备的CdS修饰低密度TiO₂纳米棒复合膜在太阳电池器件中具有很好的应用前景。

Preparation of the composite film based on CdS-modified TiO2 nanorod array with low density and its photoelectrochemical properties

In order to increase the filling ratio of CdS photosensitized layer into the TiO₂ array, a low-density TiO₂ nanorod array with short-length rods and large rod-interval is prepared based on the TiO₂ seed layer-coated FTO conductive glass through hydrothermal process. CdS seed layer is covered onto the TiO₂ nanorod by chemical bath deposition. Then CdS photosensitized layer is grown in the TiO₂ nanorod array via hydrothermal approach. SEM, XRD, UV-Vis absorption spectra are employed to characterize the TiO₂/CdS composite films with different hydrothermal time of CdS. The photoelectrochemical properties of the TiO₂/CdS composite film are also studied. The results indicate that the low-density of the TiO₂ nanorod array could facilitate the infiltration of the CdS growth solution into the TiO₂ array to form the perfect coverage with CdS seed layers. CdS photosensitized layers are homogeneously grown on the whole TiO₂ nanorods and gradually filled in the TiO₂ array through hydrothermal process. Meanwhile, flower-like CdS modified layers composed with short-length rods are formed at the top of composite film array. The light absorption of the TiO₂ nanorod array is extended to the visible region with the CdS modification. The photocurrent of the TiO₂/CdS composite film is obtained via 7 h hydrothermal growth of CdS layer. The excellent photoelctrochemical performance of the composite film of CdS modified TiO₂ nanorod array with low density reveales its application prospect in solar cells.