Study of carrier capture and vertical transport in quantum well heterostructures
We study experimentally and theoretically both vertical transport in the barriers of GaAs/AlGaAs quantum well (QW) heterostructures and the capture of electron-hole pairs into the QWS. By a numerical simulation we determine ambipolar diffusivities, mobilities, surface-recombination velocities, transmission and capture parameters for 40 K <or=T<or=150 K. Alloy-disorder scattering is found to limit the ambipolar mobilities between 40 and 120 K in the Al0.5Ga0.5As barriers.