Institute of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University, Jerusalem 91904, Israel.
ACS Nano. 2010 Oct 26;4(10):5962-8. doi: 10.1021/nn1018208.
Quantum dot sensitized solar cells (QDSSC) may benefit from the ability to tune the quantum dot optical properties and band gap through the manipulation of their size and composition. Moreover, the inorganic nanocrystals may provide increased stability compared to organic sensitizers. We report the facile fabrication of QDSSC by electrophoretic deposition of CdSe QDs onto conducting electrodes coated with mesoporous TiO(2). Unlike prior chemical linker-based methods, no pretreatment of the TiO(2) was needed, and deposition times as short as 2 h were sufficient for effective coating. Cross-sectional chemical analysis shows that the Cd content is nearly constant across the entire TiO(2) layer. The dependence of the deposition on size was studied and successfully applied to CdSe dots with diameters between 2.5 and 5.5 nm as well as larger CdSe quantum rods. The photovoltaic characteristics of the devices are greatly improved compared with those achieved for cells prepared with a linker approach, reaching efficiencies as high as 1.7%, under 1 sun illumination conditions, after treating the coated electrodes with ZnS. Notably, the absorbed photon to electron conversion efficiencies did not show a clear size-dependence indicating efficient electron injection even for the larger QD sizes. The electrophoretic deposition method can be easily expanded and applied for preparations of QDSSCs using diverse colloidal quantum dot and quantum rod materials for sensitization.
量子点敏化太阳能电池（QDSSC）可以通过操纵其尺寸和组成来调整量子点的光学性质和带隙，从而受益。此外，与有机敏化剂相比，无机纳米晶体可能提供更高的稳定性。我们报告了通过在涂有介孔 TiO(2)的导电电极上电泳沉积 CdSe QD 来制备 QDSSC 的简便方法。与以前基于化学连接剂的方法不同，不需要对 TiO(2)进行预处理，并且沉积时间短至 2 小时就足以进行有效的涂层。横截面化学分析表明，Cd 含量在整个 TiO(2)层中几乎保持不变。研究了沉积对尺寸的依赖性，并成功地应用于直径为 2.5 至 5.5nm 以及更大的 CdSe 量子点的 CdSe 点。与使用链接方法制备的电池相比，器件的光伏特性得到了极大改善，在 1 个太阳光照条件下，用 ZnS 处理涂层电极后，效率高达 1.7%。值得注意的是，吸收光子到电子的转换效率没有表现出明显的尺寸依赖性，这表明即使对于较大的 QD 尺寸，电子注入也很有效。电泳沉积方法可以很容易地扩展并应用于使用各种胶体量子点和量子棒材料进行敏化的 QDSSC 的制备。
