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The band offsets between the Zn-IV-N2 nitrides, ZnGeN2 and ZnSnN2, and two other closely lattice matched semiconductors, ZnO and GaN, are calculated using density functional theory calculations including quasiparticle corrections. The interface dependence as well as the role of strain are investigated. A staggered type-II alignment is found between ZnGeN2, GaN, and ZnO, with ZnO having the lower and ZnGeN2 having the higher valence band maximum. The potential benefits of this alignment for photovoltaic applications are pointed out. [ABSTRACT FROM AUTHOR]

We present band gaps, electron effective masses, and valence band effective-mass Hamiltonian parameters as well as strain deformation potentials of the crystal field splittings for AIN, GaN, and InN obtained from quasiparticle self-consistent GW calculations. Excellent agreement is obtained with experimental data for the crystal field and spin-orbit coupling spfittings of bulk AIN and GaN. For InN, the discrepancy on the crystal field splitting is likely due to the residual strain in InN thin films from which that experimental value was extracted. We obtain a negative spin-orbit splitting for InN, which is plausible in view of the stronger negative contribution of ln-4d in InN than Ga-3d in GaN. The inverse effective-mass parameters A¡ agree well with previous Go Wo calculations except ioi A. We find that the A(, parameter describing the band dispersion in directions intermediate between parallel and perpendicular to the basal plane is not well described by the quasicubic approximation. Good agreement with the most reliable experimental data is obtained for hole effective-mass parameters in AIN and GaN, extracted from exciton binding energies and their fine structure. For InN and GaN, the spin-splittings of the bands in the plane due to spin-orbit coupling requires the inclusion of linear in k and spin terms. [ABSTRACT FROM AUTHOR]

Electronic energy-band structures of the Zn-IV-N2 compounds, with IV equal to Si, Ge, and Sn calculated in the quasiparticle self-consistent GW approximation and using the full-potential linearized muffin-tin orbital approach, are presented. A comparison is made with local-density approximation results. The bands near the gap are fitted to an effective Kohn-Luttinger-type Hamiltonian appropriate for the orthorhombic symmetry, and conduction-band effective masses are presented. Exciton binding energies and zero-point motion corrections to the gaps are estimated. While ZnSiN2 is found to be an indirect gap semiconductor, ZnGeN2 and ZnSnN2 are direct gap semiconductors. The gaps range from the orange-red to deep UV. The valence-band maximum is split in three levels of different symmetry, even in the absence of spin-orbit coupling, and should show transitions to the conduction band, each for a separate polarization. Spin-orbit effects are found to be surprisingly small, indicating almost exact compensation of the N-2p and Zn-3d contributions. [ABSTRACT FROM AUTHOR]