Theoretical and experimental picosecond photoluminescence studies of the quantum-confined Stark effect in a strongly coupled double-quantum-well structure

Time-resolved photoluminescence measurements as a function of perpendicular applied electric field and temperature are reported in a GaAs-${\mathrm{Al}}_{\mathrm{x}}$ ${\mathrm{Ga}}_{1\mathrm{-}\mathrm{x}}$As strongly coupled double-quantum-well (CQW) structure. The excitonic radiative lifetime is found to increase with field at a rate ≊3 times faster than previously observed in single-QW structures of the same overall width, and a three-dimensional envelope-function calculation is shown to provide an excellent quantitative description of this effect, demonstrating the validity of this type of calculation for both the energies and oscillator strengths of radiative transitions. Variable temperature experiments are used to probe exciton center-of-mass motion allowing the mean exciton localization area (due to interface fluctuations) to be measured.