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 Cu2CdGeSe4 in solar cells.