Green emissions and related defects in ZnO:Ga thin films

► ZnO:Ga (GZO) films were grown under different oxygen partial pressure (PO2). ► Green emissions of GZO films were strongly influenced by PO2. ► Green emissions consist of two bands, located at 2.50 eV and 2.65 eV, respectively. ► Two bands correspond to transitions (GaZn, VZn) and (GaZn, Oi), respectively. ► Concentrations of VZn and Oi were increased with the increasing PO2.