Optical properties of ZnSSe/ZnMgSSe quantum wells

We study the electronic structure and excitonic properties of ZnSxSe1-x/Zn0.85Mg0.15S0.21Se0.79 single quantum wells through an exact treatment of the Pikus-Bir Hamiltonian, In the ZnSe well, we find three distinguished exciton peaks in the absorption spectra, which are associated with the n = 1 and 2 heavy holes (HH1 and HH2) and n = 1 light hole (LH1), in good agreement with experiments. As the S content of the well increases, the HH1 exciton peak increases more rapidly than the LH1 peak, and a severe overlap between these two peak appears at x = 0.1. The binding energy of the HH1 exciton also increases with the S content; however, its maximum value decreases because of the decreasing confinement effect in the well.