Material property tuning for nanophotonic applications

Material property engineering provides great opportunities to achieve novel applications in various fields, for example, in nanophotonics. By utilizing chemical intercalation or ionic liquid gating methods, we have demonstrated dynamic tuning of optical properties of bismuth chalcogenide nanoplates. In the meantime, we also developed a new theory showing that permittivity gradient along a semiconductor surface enables direct coupling between free-space light and surface plasmon polariton modes. Combined with material property tuning methods, our theory paves a new route towards future plasmonic device applications.