Time-resolved photoluminescence of spatially direct and indirect transitions in GaAs /AlxGa1-xAs wires

Time-resolved photoluminescence studies have been performed on shallow etched wires prepared from remote-doped GaAs/AlxGa1-xAs quantum wells. A fast decay is observed for the direct excitonic transitions below the experimental resolution of 10 ns. The indirect luminescence decays nonexponentially with a differential lifetime increasing from 30 to more than 1000 ns. At the same time the transitions shift to lower energies due to an increasing potential modulation. Numerical simulations reveal a good agreement with the measured differential lifetimes.