Coupling Quantum Emitters to Random 2D Nanoplasmonic Structures

We combine theory and experimental studies to investigate the coupling between colloidal quantum dots and randomly generated gold nanoislands. In such devices, the gold nanoislands act as classical antennas, amplifying the light absorbed by the quantum dots. They may thus find applications in detection, sensing, and plasmon-enhanced solar energy conversion. We use the two-dimensional finite-difference time-domain method to demonstrate plasmonic control of the enhancement factor near the island's plasmon resonance. Furthermore, we experimentally and numerically show how tuning the plasmon resonance to the band gap energy of the quantum dot can lead to a broadening of the quantum dot's absorption peak. The simulations predict a surprising linear scaling with quantum dot density, which is confirmed by experimental results.