First-principles study on native point defects of cubic cuprite Ag₂O

Using the first-principles calculations, we have systematically investigated the atomic configurations, electronic structures, formation energies and transition energies of native point defects in cuprite Ag₂O. Under the conditions of Ag-rich, we find that the oxygen vacancy (V_O) and the oxygen interstitial (O_i) have the lowest formation energies in p-type and n-type conditions, respectively. Silver vacancy (V_Ag) acts as a shallow acceptor, which has high formation energy in p-type sample. Oxygen anti-site (O_Ag) is the most stable state and acts as an acceptor-type point defect in the O-rich conditions. Ag interstitial (Ag_i) is a shallow donor, which can be formed easily in the Ag-rich conditions. Moreover, we study the band offsets of heterojunction between Ag₂O in cuprite structure and ZnO, GaN, and AlN in the wurtzite structure. These results would provide guidance for the experimental studies of point defects in cuprite Ag₂O.