Quantum unconfined Stark effect in a GaAs single quantum well: An optical-constant model

A theoretical model for high-field electroabsorption in a single GaAs quantum well (QW) is presented. Electron and hole properties are modeled with a transfer-matrix technique which includes the nonparabolicity of the energy bands. This model adequately reproduces the coupling between quasibound and continuum states resulting from the influence of a large transverse electric (TE) field on a QW with a finite barrier height. The absorption coefficient has been calculated by the program opcons for the TE mode in the QW structure for electric fields ranging from 100 to 500 kV/cm. Our calculations predict an absorption coefficient in reasonable agreement with the experimental data, and with a simpler model based on the one-electron overlap integral picture.