Calculation of gain?current characteristics in ZnCdSe?ZnSe quantum well structures including many body effects.

Abstract

The gain-spontaneous recombination characteristics have been calculated for a 40 ? Zn0.8Cd0.2Se-ZnSe quantum well including many body effects. We examine the effect of the inclusion of the Coulomb enhancement on the gain spectra and the gain-current relationship. We show that, in the absence of the Coulomb enhancement, the threshold current density of a 340 ?m 40 ? Zn0.8Cd0.2Se-ZnSe quantum well laser is underestimated by approximately 40% and the lasing wavelength overestimated by 4 nm. Our calculation of the scattering lifetime for the first electron-heavy hole transition gives a lifetime varying between 29 and 37 fs, and shows that the carrier-phonon scattering mechanism in II-VI quantum wells is more dominant than in III-V materials. We also comment on the effect the neglect of Coulomb enhancement has on the calculation of leakage currents in a laser at threshold.