Light-controlled conductance switching of ordered metal-molecule-metal devices.

We demonstrate reversible, light-controlled conductance switching of molecular devices based on photochromic diarylethene molecules. These devices consist of ordered, two-dimensional lattices of gold nanoparticles, in which neighboring particles are bridged by switchable molecules. We independently confirm that reversible isomerization of the diarylethenes employed is at the heart of the room-temperature conductance switching. For this, we take full advantage of the possibility to use optical spectroscopy to follow molecular switching in these samples.