Structural, electronic and optical properties of orthorhombic CdGeO3CdGeO3 from first principles calculations

Orthorhombic perovskite CdGeO3CdGeO3 was studied using the density-functional theory (DFT) formalism. The electronic band structure, density of states, effective masses, dielectric function and optical absorption were obtained. Comparing with orthorhombic CaGeO3CaGeO3, which is an indirect S→ΓS→Γ gap material, the substitution of calcium by cadmium changes the valence band maximum from the S   point to the ΓΓ point in reciprocal space, and decreases the Kohn–Sham band gap energy. Our results suggest that orthorhombic CdGeO3CdGeO3 has features of a semiconductor and is potentially useful for optoelectronic applications.

Graphical Abstract Legend (TOC Figure)Different views of the unit cell of orthorhombic CdGeO3CdGeO3 (left, top). The electronic band structure near the main gap and the partial density of states (PDOS) are shown also (right), as well as the optical absorption for different polarizations of incident light (left, bottom).Figure optionsDownload as PowerPoint slide