Native defects and hydrogen impurities in Ag3PO4

Silver orthophosphate (Ag3PO4) exhibits extremely high photocatalytic activity under visible light. Gaining insight into the behavior of point defects would open opportunities for new applications. Our hybrid density-functional calculations show that intrinsic point defects are unlikely to cause carrier trapping. Charge neutrality analysis suggests that Ag3PO4 possibly behaves as a weak n-type semiconductor under the O-poor condition and as a weak p-type semiconductor under the O-rich condition. Unlikely to other oxides, unintentionally incorporated hydrogen does not necessarily lead to strong n-type conductivity. Migration properties of some Ag-related defects and hydrogen are also discussed.