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 s tates in strained, piezoelectric quantum wells, grown on the 111 direc tion in the InGaAs-GaAs material system, in the presence of screening by excited carrier pairs. We show that for devices of practical intere st the electronic structure is largely independent of the magnitude of the electric field in the barriers and is determined by the mean held in the well, even when this results from screening of the piezoelectr ic 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.