Enhancement of light emission and internal quantum efficiency in orange and red regions for regularly arrayed InGaN/GaN nanocolumns due to surface plasmon coupling

We demonstrate enhanced light emission in the orange and red regions from regularly arrayed InGaN/GaN nanocolumns due to the surface plasmon (SP) coupling. A maximum photoluminescence (PL) enhancement ratio of 5.2 is observed by coating the nanocolumns with an Au thin film. In addition, a 2.1-fold increase in the internal quantum efficiency is obtained. Comparison of an electromagnetic field simulation and a theoretical calculation based on the SP dispersion indicates that the SP originates from a standing wave mode arising from the periodic Au/dielectric interface. The column-diameter dependence of the PL enhancement ratio can be reasonably explained by considering the simulated electric field intensity. The periodic plasmonic nanostructure is effective for improving the emission efficiencies of InGaN-based light emitters in the orange and red regions.