Superradiance in GaN-(Al,Ga)N resonant Bragg structures with single and double quantum wells in the unit supercell

We demonstrate the effect of superradiant exciton–polariton mode formation at room temperature in the reflection spectra from resonant Bragg structures (RBSs) composed of GaN quantum wells (QWs) separated by Al0.15Ga0.85N barriers. We have developed and created RBS with single and double GaN QWs in the unit supercell. Double GaN/(Al,Ga)N QWs fabrication in RBS provides record room temperature performance compared to other structures. Decreasing the built-in electric fields in a complex unit supercell results in a record-high radiative broadening ℏΓ0 of excitons in GaN QW equal to 0.5 ± 0.02 meV. We also demonstrate that implementation of the complex unit supercell in RBS is a way to enhance the photon–exciton coupling and to address the problems related to optical losses and small variations of thickness of the (Al,Ga)N barriers.