Manna Liberato, Scher Erik C, Li Liang-Shi, Alivisatos A Paul
Department of Chemistry, University of California, Berkeley, 94720, USA.
J Am Chem Soc. 2002 Jun 19;124(24):7136-45. doi: 10.1021/ja025946i.
We report the preparation and structural characterization of core/shell CdSe/CdS/ZnS nanorods. A graded shell of larger band gap is grown around CdSe rods using trioctylphosphine oxide as a surfactant. Interfacial segregation is used to preferentially deposit CdS near the core, providing relaxation of the strain at the core/shell interface. The reported synthesis allows for variation of the shell thickness between one and six monolayers, on core nanorods ranging from aspect ratios of 2:1 to 10:1. After an irreversible photochemical annealing process, the core/shell nanorods have increased quantum efficiencies and are stable in air under visible or UV excitation. In addition to their robust optical properties, these samples provide an opportunity for the study of the evolution of epitaxial strain as the shape of the core varies from nearly spherical to nearly cylindrical.
我们报道了核壳结构CdSe/CdS/ZnS纳米棒的制备及其结构表征。使用三辛基氧化膦作为表面活性剂，在CdSe棒周围生长具有较大带隙的渐变壳层。利用界面偏析优先在核附近沉积CdS，从而缓解核壳界面处的应变。所报道的合成方法能够使壳层厚度在1至6个单分子层之间变化，应用于长宽比在2:1至10:1范围内的核纳米棒。经过不可逆的光化学退火过程后，核壳纳米棒的量子效率提高，并且在可见光或紫外光激发下在空气中稳定。除了具有强大的光学性能外，这些样品还为研究随着核的形状从近球形变为近圆柱形时外延应变的演变提供了机会。
