Atomistic tight binding study of quantum confined Stark effect in GaBixAs1-x/GaAs quantum wells

Abstract

Recently, there has been tremendous research interest in novel bismide semiconductor materials (such as GaBixAs1-x) for wavelength-engineered, low-loss optoelectronic devices. We report a study of the quantum confined Stark effect (QCSE) computed for GaBixAs1-x/GaAs quantum well (QW) structures based on large-scale atomistic tight-binding calculations. A comprehensive investigation of the QCSE as a function of the applied electric field orientations and the QW Bi fractions reveals unconventional character of the Stark shift at low Bi compositions (x = 3.125%). This atypical QCSE is attributed to a strong confinement of the ground-state hole wave functions due to the presence of Bi clusters. ..