Effect of guided resonance modes on emission from GaN core–shell nanorod arrays

We model the process of incoherent emission from In_xGa_1-xN/GaN quantum wells in GaN core–shell nanorod arrays using finite-difference time-domain simulations. We find that high-intensity features in the emitted field correspond to guided resonance modes near the -point of the photonic band structure. We identify one -point mode whose electric field intensity profile is ideal for core–shell nanorod array geometries. Using this mode, we are able to simultaneously enhance the radiative recombination rate and extraction efficiency relative to an in-filled slab. We determine the conditions on radiative and nonradiative recombination rates for which the nanorod array has a higher internal and external quantum efficiency than a reference slab. We present one nanorod array geometry where the external quantum efficiency is enhanced up to a factor of 25.