Ambipolar diffusion anisotropy induced by defects in nipi-doped In0.2Ga0.8As/GaAs multiple quantum wells

Abstract
The influence of strain-induced defects on the ambipolar diffusive transport of excess electrons and holes in the δ-doped InGaAs/GaAs multiple quantum well system has been examined with a new technique called electron-beam-induced absorption modulation (EBIA). The excess carrier lifetime and diffusion coefficient are obtained by a one-dimensional diffusion experiment that utilizes EBIA. An anisotropy in the ambipolar diffusion along both high-symmetry 〈110〉 directions is found, and this is seen to correlate with the distribution of dark line defects observed in cathodoluminescence.