Electronic structure of ZnGeP2: A detailed study of the band structure near the fundamental gap and its associated parameters

Full-potential linear muffin-tin orbital band-structure calculations of ZnG eP2 in the local-density approximation (LDA) indicate several close-lying c onduction-band minima at different points in the Brillouin zone. Quasiparti cle results available for the zinc-blende "parent" compound GaP are used to estimate corrections beyond the LDA. Even including these corrections, ZnG eP2 appears to be truly indirect rather than pseudodirect, as has been sugg ested in the literature. The experimental evidence is reviewed. The standar d assignment of features in optical data pertaining to the absorption edge is questioned and a tentative new interpretation is presented in light of o ur multiple conduction-band minima model. Related band-structure parameters , such as band-gap deformation potentials, effective masses at each of the minima, and the valence-band effective Hamiltonian are determined. [S0163-1 829(99)01835-4].