Fast escape of photocreated carriers out of shallow quantum wells

Publisher Website
Google Scholar
Abstract
We report that at room temperature the field‐induced escape of photogenerated carriers out of shallow GaAs/AlxGa1−xAs multiple quantum wells is as fast as for pure GaAs of the same thickness, if the value of x does not exceed 0.04. Our experimental findings can be explained by assuming that carriers are efficiently scattered into the unconfined barrier states by absorption of a LO phonon, as long as the effective barrier height is less than the LO‐phonon energy. The application of shallow quantum wells with x≤0.04 in self‐electro‐optic effect devices, providing not only strong excitonic electroabsorption but also fast sweep‐out times at small biases, should lead to shorter switching times.