Invited
LITHOGRAPHICALLY TEMPLATED ORGANIZATION OF NANODUMBBELLS

Nanodumbbells - 1D semiconductor nanorods with chemically grown Au tips - were first synthesized almost one and a half decades ago (Mokari et al, Science 304, 1787, 2004). The chemical attachment of Au nanotips was motivated by the formation of natural anchor points that can serve as recognition elements for directed self-assembly. However, despite the long time passed since this discovery, and the fact that site-selective growth, which has been demostrated since then for many materials and nanostructures, became an important field of nanoscience, the original concept of directed assembly via chemically grown anchors has not been realized up until now.

In this work, we demonstrate, for the first time, the directed assembly of nanodumbells via chemical “docking” to nanopatterned anchoring functionalities. We realized the functionalities through nanoimprinted sub-10 nm metallic nanodots functionalized to chemically bind the nanodumbbell tips, and by this way, encode their assembly into controlled 2D higher architectures. For the binding, we used simple and robust chemistry based in dithiol molecules that bind to both nanodumbbell tips and the docking nanodots. We showed, that by arbitrarily varying the geometry of the nanodot arrays, it is possible to program whether the nanodumbbells would dock with one or two of their edges, determining thereby the configuration of the obtained assembly. We also investigated the kinetics of the docking based nano-assembly, and found that it can be described Random Attachment Model that eliminates any interaction between the nanodumbbells docked to the same nanodot. Our work demonstrates the potential for massively parallel positioning of sub-100 nm 1D semiconductor nanostructures, and opens a pathway to their integration into functional nanodevices and nanosystems.