Calculations of interdiffusion and the quantum-confined Stark effect in GaAs-GaAlAs quantum wells

Abstract

The partial intermixing of well and barrier materials offers unique opportunities to shift locally the bandgap of quantum well (QW) structures. In combination with the quantum confined Stark effect it can be used for many applications in integrated optoelectronics. Here we investigate theoretically the optical and electro-optical properties of partially intermixed GaAs-GaAlAs QW structures. We calculate the dependences of energy shifts and absorption spectra as a function of the well width, the interdiffusion length and the applied electric field. We show in particular that large blue shifting by interdiffusion and efficient electro-optical modulation can be achieved only for a narrow range of QW widths.