Dependence of cuprous oxide conductivity on metal doping: a hybrid density functional simulation

Multiple metallic elements were screened as doping agents to alternate conductivity in cuprous oxide (Cu 2 O). Energetic, charge transition levels and optical properties of Be, Mg, Ca, Sr, Zn, Cd, Hg, Al, Ga, and In substitutionally doped Cu 2 O systems were investigated based on first principles methods. Results of formation energy calculation under both Cu-rich and Cu-poor conditions indicate the easy incorporation of 2A (Be, Mg, Ca, and Sr) group impurities into the crystal lattice of Cu 2 O under both conditions. However, 3A (Al, Ga, and In) group impurities could be incorporated only under Cu-poor conditions. While, the incorporation of Zn, Cd, and Hg in Cu 2 O is energetically less favorable under both conditions. The calculated charge transition levels of these dopants revealed an n-type conductivity. The calculated work functions show n-type to p-type surface inversion behavior for some doped systems. This can explain the p-type conductivity of Mg-doped Cu 2 O found experimentally. Furthermore, the optical properties of each system are calculated to investigate the effect of the introduced impurity on Cu 2 O. This study can help identify potential dopants to use for solar cell fabrication. Graphical abstract