Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089, United States.
Nano Lett. 2011 Jul 13;11(7):2887-91. doi: 10.1021/nl201351f. Epub 2011 Jun 27.
We present a new approach to ligand exchange on lead sulfide (PbS) quantum dots (QDs) in which the QDs are reacted with preformed Pb cation-ligand exchange units designed to promote reactions that replace surface Pb and oleate groups on the as-grown QDs. This process introduces negligible surface defects as the high quantum efficiency (∼55%) of the as-grown QDs is maintained. Infrared spectroscopy and electron microscopy are used to confirm the replacement of ligands and time-resolved photoluminescence to demonstrate the expected inverse sixth power dependence of the nonradiative resonant energy transfer rate on inter-QD spacing.
我们提出了一种在硫化铅（PbS）量子点（QD）上进行配体交换的新方法，该方法是将 QD 与预先形成的 Pb 阳离子-配体交换单元反应，以促进取代生长 QD 表面上的 Pb 和油酸盐基团的反应。该过程引入的表面缺陷可忽略不计，因为生长 QD 的高光量子效率（约为 55%）得以保持。红外光谱和电子显微镜用于确认配体的取代，时间分辨光致发光用于证明非辐射共振能量转移率对 QD 间距的预期逆六次幂依赖性。
