Investigation of Structural and Electronic properties of Cuprous oxide using density functional theory

Abstract

In this thesis the Structural and electronic properties of Cuprous Oxide (Cu2O) is investigated with density functional theory (DFT) using Quantum Espresso package. Our study is based on Density Functional Theory (DFT) with the Perdew-Burke- Ernzerhof (PBE) exchange-correlation functional, Vanderbilt (ultra soft) pseudopotentials and the plane wave basis set implemented in the Quantum-ESPRESSO package. The total minimum energy and the total minimum force of Cu2O is calculated as a function of cutoff energy and K-points sampling. The total minimum energy per cell is monotonically decreased with increased cutoff energy due to variational principle. However, this trend can not be predicted from increasing the k-points sampling. Moreover, the equilibrium lattice constant is calculated using results obtained from energy convergence test (i.e., 50 Ry and 7 × 7 × 7 ). The computational value of the equilibrium lattice constant is 4.32 °A. This result is in good agreement with experimental value which is 4.27 °A. Finally, discussing band structure and density of state of three dimensional Cu2O, the electrical property of three dimensional Cu2O is determined based on energy band gap.