Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, P. R. China.
Phys Chem Chem Phys. 2013 Dec 7;15(45):19595-600. doi: 10.1039/c3cp52678j. Epub 2013 Aug 20.
Halogen ions (I(-), Br(-), Cl(-)) were added into a colloidal solution of CdSe and PbS quantum dots (QDs) to form QDs capped with these inorganic ligands. Halogen ions attached to QDs through electrostatic interactions and the varying coordination strength between the inorganic ligands and QDs led to different degrees of redispersion and stabilization in polar solvents. Moreover, we successfully conducted electrophoretic deposition (EPD) of QDs capped with inorganic ligands. Negatively charged QDs were adsorbed onto a positively charged TiO2 anode. The assembled QDs films were used in photovoltaic devices and offered better efficiency than QDs capped with organic ligands. This work demonstrates that halogen ions are indeed promising ligands to improve the stability of QDs with inorganic ligands and the EPD method shows prospects in assembling QDs films for practical applications.
卤素离子（I(-)、Br(-)、Cl(-)）被添加到 CdSe 和 PbS 量子点的胶体溶液中，形成了这些无机配体包覆的量子点。卤素离子通过静电相互作用附着在量子点上，而无机配体与量子点之间的配位强度的变化导致了在极性溶剂中不同程度的再分散和稳定。此外，我们成功地进行了带有无机配体的量子点的电泳沉积（EPD）。带负电荷的量子点被吸附到带正电荷的 TiO2 阳极上。组装好的量子点薄膜被用于光伏器件，其效率优于带有有机配体的量子点。这项工作表明，卤素离子确实是改善带有无机配体的量子点稳定性的有前途的配体，而电泳沉积方法在组装量子点薄膜以用于实际应用方面显示出了前景。
