Electronic, Optical and Elastic Properties of Cu₂CdGeSe₄: A First-Principles Study

Using the augmented plane wave + local orbitals method with different approximation functionals, we investigate systematically the electronic, optical and elastic properties of stannite-type Cu₂CdGeSe₄. Among different approximation functionals, the modified Becke–Johnson (mBJ) potential with Hubbard-corrected parameter U (mBJ + U) gives the most reliable results on the electronic properties of Cu₂CdGeSe₄ in comparison with the experimental data. Elastic modulus, elastic constants and the Poisson’s ratio of Cu₂CdGeSe₄ were calculated using the Elastic software package. Optical properties such as wide spectrum of absorbed photon energy, namely 1.3–27.2 eV, high absorption coefficient (above 10⁴ cm⁻¹) and optical anisotropy suggest the application of Cu₂CdGeSe₄in solar cells.