Imaging of Matter
How gold crystals catch light
14 July 2022
Photo: Florian Schulz
What happens when light strikes supercrystals that deviate from the simplest geometries? In a project funded by the German Research Foundation, researchers from Hamburg and Berlin want to precisely recreate such structures and study their interaction with light.
In a seminal work published in Nature, a team of researchers led by Stephanie Reich, professor at FU Berlin, Dr. Florian Schulz and Dr. Holger Lange of Universität Hamburg already demonstrated extremely strong light-matter interaction with periodically ordered metal nanoparticles. Whether light is guided through these so-called supercrystals, focused into the gaps between the nanoparticles or absorbed in them depends on the supercrystal geometry. This offers the possibility to "design" light-matter interaction.
In the project recently approved by the DFG, the team now wants to create and study structures that deviate from the simplest geometry, the densest packing of spheres. To do this, the researchers plan to combine nanoparticles of two sizes to form binary supercrystals, for example, and then replicate the rock salt lattice structure.
"We expect the light to be focused into the gaps," says Holger Lange, who, like Florian Schulz, conducts research in the Cluster of Excellence "CUI: Advanced Imaging of Matter." Combined with light-emitting dyes or photocatalysts, the team hopes for directed, more intense light pulses from the dyes, or an improvement in photocatalytic efficiency.
The DFG is funding the joint project of FU Berlin and the University of Hamburg with half a million euros.
Further information:
N. S. Mueller, Y. Okamura, B. G. M. Vieira, S. Juergensen, H. Lange, E. B. Barros, F. Schulz, St. Reich
"Deep strong light–matter coupling in plasmonic nanoparticle crystals"
Nature 583, 780 – 784 (2020)