Friday, May 1, 2015

The world smallest crak created by UCSD

Interesting work on making the smallest possible crack using graphene or so called nano gaps. In this case the use of single-layer graphene is used as a template for the formation of subnanometer plasmonic gaps using a scalable fabrication process called “nanoskiving.” The research was carried out by the University of California, San Diego (UCSD) and has been published in the journal Nano Letters.


Athermally photoreduced graphene oxides for three-dimensional holographic images
Aliaksandr V. Zaretski , Brandon C. Marin , Herad Moetazedi , Tyler J. Dill , Liban Jibril , Casey Kong , Andrea R. Tao , and Darren J. Lipomi
Nano Lett., 2015, 15 (1), pp 635–640, DOI: 10.1021/nl504121w

Abstract Image

This work demonstrates the use of single-layer graphene as a template for the formation of subnanometer plasmonic gaps using a scalable fabrication process called “nanoskiving.” These gaps are formed between parallel gold nanowires in a process that first produces three-layer thin films with the architecture gold/single-layer graphene/gold, and then sections the composite films with an ultramicrotome. The structures produced can be treated as two gold nanowires separated along their entire lengths by an atomically thin graphene nanoribbon. Oxygen plasma etches the sandwiched graphene to a finite depth; this action produces a subnanometer gap near the top surface of the junction between the wires that is capable of supporting highly confined optical fields. The confinement of light is confirmed by surface-enhanced Raman spectroscopy measurements, which indicate that the enhancement of the electric field arises from the junction between the gold nanowires. These experiments demonstrate nanoskiving as a unique and easy-to-implement fabrication technique that is capable of forming subnanometer plasmonic gaps between parallel metallic nanostructures over long, macroscopic distances. These structures could be valuable for fundamental investigations as well as applications in plasmonics and molecular electronics.



Figure text