Superradiance from one-dimensionally aligned ZnO nanorod multiple-quantum-well structures

Using one-dimensionally aligned ZnO nanorod multiple-quantum-well structures (MQWs), we observed a superradiance, i.e., a cooperative spontaneous emission. We confirmed that the excitation power dependence of the emissions from the MQWs originated from the coherent coupling of the QWs due to the well organization at nanoscale. We identified two QWs with cooperative emission. Additionally, we evaluated the number of coherently coupled QWs sets of four that resulted in the superradiance. Our findings provide criteria for designing nanoscale synergetic devices without the use of an external cavity.