Photoluminescence lifetime of AlAs/GaAs disordered superlattices

Abstract

Time-resolved photoluminescences (PL) of AlxGa1-xAs (0≤x≤0.5) bulk alloys, AlAs/GaAs ordered superlattices, and AlAs/GaAs disordered superlattices are measured at 77 K and compared. The PL lifetimes of the AlAs/GaAs disordered superlattices were always shorter than those of the Al0.5Ga0.5As bulk alloy and the AlAs/GaAs ordered superlattices with indirect band gaps. These shorter PL lifetimes of the disordered superlattices suggest a relaxation of the momentum conservation during radiative recombination by intentional disordering.