Photoluminescence dependence on heterointerface for MOCVD grown GaInNAs/GaAs QWs

We investigated the effect of the gas flow sequence of dimethylhydrazine (DMHy) at heterointerfaces on the optical quality of GaInNAs/GaAs grown by metalorganic chemical vapor deposition (MOCVD). We point out that the photoluminescence (PL) degradation of GaInNAs grown by MOCVD can be categorized into two types. One is the formation of a GaNAs layer at the interface which causes both an unexpected wavelength extension and degradation of crystal quality. Another is introduction of non-radiative centers by N incorporation itself. To overcome these degradation mechanisms, the insertion of GaInAs to the GaInNAs/GaAs heterointerface is proposed. A GaInAs intermediate layer (IML) suppresses GaNAs formation and improve the optical quality of GaInNAs QWs.