Electronic structure and field screening effects in 111 InGaAs-GaAs strained layer piezoelectric quantum-wells

In this paper we study the electronic structure of the lowest energy states in strained, piezoelectric quantum wells, grown on the 111 direction in the InGaAs-GaAs material system, in the presence of screening by excited carrier pairs. We show that for devices of practical interest the electronic structure is largely independent of the magnitude of the electric field in the barriers and is determined by the mean field in the well, even when this results from screening of the piezoelectric fields by internal charge redistribution. We then present a simple method for estimating field screening effects and report calculations of optimum internal field for optoelectronic applications.<>