Lab talk
Jun 8, 2010
Quasi-3D metal nanostructure focuses plasmons
For practical applications, efficient strategies for the design of organized nanostructures, in which large field enhancements are excited by incident light, are paramount for the fabrication of reproducible, stable and highly active SERS substrates. Metal structures can guide the incident light energy flow. By adding a metal lid to periodic nanoholes, a novel quasi-3D structure has been designed to catch more extraordinary optical transmission energy for huge SERS enhancement.
Researchers at Peking University, China, are studying a new generation of sensors based on extraordinary optical transmission (EOT) because these nanostructures support the unusual phenomenon of EOT. The scientists add metal lids to conventional periodic nanoholes to build up novel quasi-3D structured, periodic arrays of two-layer coupled quadrate-holes and squares for SERS applications.
According to calculations, the top metal layer's job appears to be the collection and transport of energy to the gap between the edges of the structure by coupling with the bottom metal square. Both experiment and simulation show the advantages of the quasi-3D structure over the structure of one-layer nanoholes for SERS enhancement.
More details can be found in the journal Nanotechnology.
About the author
This work was performed at the Institute of Condensed Matter (ICM), School of Physics, Peking University, Beijing, China. All of the authors are members of the State Key Laboratory for Mesoscopic Physics and work at the ICM. Dr Yumin Hou is an associated professor with experience in both theoretical and experimental work. Her research interests include the behaviour of electrons, from strongly correlated electrons to surface plasmon polaritons, from fundamental physics to its potential application. Jun Xu is a senior engineer and Dr Xuejin Zhang is a postdoc. Dr Da-peng Yu is the head of the group for nanostructures and low-dimensional physics.
![Electric field distribution around the metal "lids"](http://images.iop.org/objects/ntw/journal/9/6/6/image1.jpg "Electric field distribution around the metal "lids"")