Lateral localization effects in strained InGaAs/GaAs semiconductor quantum wells grown on vicinal surfaces

We have studied different strained InGaAs/GaAs ultrathin quantum wells grown on vicinal surfaces for various terrace lengths and In contents. From photoluminescence experiments we observe an enhancement of the continuum density of states of quantum wells wit large In content (x equals 0.35). We associate this behavior to the localization of carriers in regions of quasi one-dimensional confinement which are induced by fluctuations in the lateral periodicity of the strained layers. This assumption is supported by time resolved measurements and explained through theoretical calculations.