Effect of disorder on the optical properties of resonant Bragg structures based on III–N

The effect of spatial and energy disorder on the formation of a superradiant exciton-polariton mode in the reflectance spectra of resonant Bragg structures (RBSs) at room temperature is studied. A limitation on the number of InGaN quantum wells (QWs) in RBS caused by critical spatial disorder is found. This disorder determines the transformation of a single superradiant optical mode into a multimode spectrum. A record high exciton oscillator strength in GaN QW compared to other material systems is experimentally achieved. The increase in the exciton oscillator strength in GaN QW compared to InGaN QW is mainly explained by a decrease in the inhomogeneous broadening of the exciton state.