四脚状CdSe敏化TiO2纳米管阵列薄膜光电性能研究

采用阳极氧化法在钛基底上生长了一维高度有序TiO2纳米管阵列,并与CdSe四脚状晶体及CdSe量子点组装成一种新型的量子点敏化太阳能电池( QDSSCs).该阵列结构为光生电子的传递提供了快速通道,CdSe四脚状三维空间结构增加了其吸附在TiO2纳米管阵列的稳定性.采用XRD,SEM和HR-TEM对阵列及CdSe四脚状和量子点进行了表征.考察了CdSe四脚状和量子点敏化纳米管阵列三电极电池结构的光电性能.XRD谱图表明TiO2的锐钛矿晶型特征峰没有发生变化,同时出现了一系列的CdSe六方晶型和立方晶型特征峰.SEM图表明所制备的TiO2具有高度有序的纳米管阵列结构,且孔径大小均一、约为120 nm,长度近13.8 μm.TEM和HRTEM图表明CdSe量子点具有四脚结构,CdSe核的直径约为4.1nm,臂宽约为3.1nm,臂长约为16.0nm.结果表明:通过四脚状CdSe修饰TiO2纳米管阵列基电极在可见光谱区域的吸收得到了明显增强；此外,在模拟太阳光(AM 1.5 100 mW·cm-2)的照射下,四脚状CdSe敏化比CdSe量子点敏化TiO2纳米管阵列三电极结构电池的光电转换效率高,它们分别为0.13％和0.30％.

Preparation and Photovoltaic Performances of CdSe Tetrapod Sensitized TiO2 Nanotube Arrays Solar Cells

CdSe tetrapod nanocrystal and quantum dots(QDs) were combined with TiO2 nanotube arrays,which were grown vertically on Ti substrate by using anodic oxidation method,to demonstrate a new type of quantum-dot-sensitized solar cells.The nanotube arrays could improve electron transport by avoiding the particle to particle hopping that occurred in the TiO2 nanocrystalline membrane and the colloidal CdSe tetrapods were immobilized over the TiO2 nanotube layers on account of tetrapod-shape structure.XRD,SEM and HR-TEM were used to characterize the nanotube and CdSe tetrapods,quantum dot.XRD results showed that samples were mixture phase with TiO2 anatase and CdSe.SEM results showed that TiO2 nanotubes were orderly arrays with diameter of about 120 nm and length of 13.8 μm.TEM showed that the CdSe quantum dots were tetrapod shape.The I-U curve showed that CdSe tetrapods could be used to sensitize the TiO2 nanotube arrays making it highly responsive to the visible spectrum.Furthermore,for three-electrode measurement,a higher power conversion efficiency of 0.30% was obtained for CdSe tetrapod sensitized TiO2 nanotube sample comparing with 0.13% for quantum dots sensitized TiO2 nanotube under AM 1.5 100 mW · cm-2 illumination.