Theoretical investigation of excitonic gain in ZnO--Mg/sub x/Zn/sub 1-x/O strained quantum wells

Free-excitonic gain of wurtzite ZnO--Mg/sub x/Zn/sub 1-x/O quantum wells(QWs) is studied theoretically. The valence band structure of ZnO--Mg/sub x/Zn/sub 1-x/O QWs with the consideration of biaxial strain and exciton-phonon interaction is calculated based on a 6/spl times/6 Hamiltonian. From the available experimental data, the band offset ratio and conduction band deformation potential of ZnO--Mg/sub x/Zn/sub 1-x/O QWs are found to be 60/40 and -6.8eV, respectively. The influence of biaxial strain on the peak free-excitonic gain of ZnO--Mg/sub x/Zn/sub 1-x/O QWs for various well-width and mole fraction of Mg is also investigated.