First-principles calculations of the structural, elastic, electronic, chemical bonding and optical properties of zinc-blende and rocksalt GeC

Structural parameters, elastic, electronic, bonding and optical properties of zinc-blende and rocksalt GeC have been investigated using the plane-wave ultrasoft pseudopotential technique based on the first-principles density-functional theory (DFT). The ground-state properties obtained by minimizing the total energy are in favorable agreement with the previous work. Two phases of GeC are found to be elastically stable and we have obtained the bulk, shear and Young’s modulus, Poisson’s coefficient and Lamé’s constants for zinc-blende and rocksalt GeC. We estimated the Debye temperature of zinc-blende and rocksalt GeC from the acoustic velocity. Electronic and chemical bonding properties have been studied. Moreover, the complex dielectric function, refractive index, extinction coefficient, optical reflectivity, absorption coefficient, energy-loss spectrum and the complex conductivity function are calculated.

Graphical abstractThe total and partial density of states of zinc-blende GeC (a) and rocksalt GeC (b).Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Bulk properties of zinc-blende and rocksalt GeC have been investigated. ► Two phases of GeC are all mechanically stable and behave in a brittle manner. ► B3-GeC is a semiconductor and B1-GeC has metallic behavior.