Role of heterointerface on enhancement of no-phonon luminescence in Si-based neighboring confinement structure

The origin of the no-phonon (NP) luminescence enhancement was explored in Si-based neighboring confinement structures (NSCs). Post growth annealing was found to lead to quenching of the NP line. Time-resolved photoluminescence study clarified that the radiative lifetime of the annealed sample increases with increasing temperature, while that of the as-grown sample shows no significant change at low temperatures (<40 K). These results are reasonably explained by considering that ‘‘in-plane’’ exciton at the heterointerface is the controlling mechanism for the NP enhancement which is observed at low temperatures in the as-grown NCS.