Gold nanosponges could be useful in computers of the future

Researcher in laboratory. Photo.

In an advanced experiment, researchers have established that nanoparticles made of metal and semiconductors have properties never previously observed. Among other things, the particles are extremely good at amplifying incident laser light. The new discovery could become very important for the development of optical computers in the future.

In a study published in the scientific journal Nature Communications, a Swedish-German team including physics researchers from Lund University, investigated how nanoparticles react to laser. Following several successful previous studies, the research team chose to study the properties of particles made of metal and semiconductors. In a laboratory in Ilmenau in Germany, a porous gold nanosponge was produced filled with zinc oxide using a method in which different types of gases are employed. This particle, with a circumference of a few hundred nanometres (one thousand-millionths of a metre), was then sent to the Lund Laser Centre where it was irradiated with laser and studied under a photoemission electron microscope.

“For the first time, we could see that light spreads randomly between the nanopores and after a period of time, concentrates in small distinct hotspots where the lifespan of the light is much longer than for the particle in general”, says Jan Vogelsang, physics researcher at Lund University.

What could be the practical applications of this discovery? The research team says the method of obtaining strong light by irradiating metal nanoparticles could be useful in the development of future optical computers. Instead of using electrons, as is done currently, nanoparticles can function as small light sources that power the computers. Another possible application could be ultrafast optical switches or transistors.

“My colleagues and I continue to work in the intersections between synchrotron radiation research and atomic physics and hope to be able to present more interesting discoveries in the future”, says Jan Vogelsang.

In addition to Lund University, the following higher education institutions participated in the study: University of Oldenburg and the Ilmenau University of Technology.

Publication: "Nonlinear plasmon-exciton coupling enhances sum-frequency generation from a hybrid metal/semiconductor nanostructure" - nature.com