Green emissions and related defects in ZnO:Ga thin films

Abstract ZnO:Ga(GZO) thin films were grown on quartz glass under different oxygen partial pressures (PO 2 ). The intensity and the profile of green emission spectra were strongly influenced by PO 2 . The PL spectra of samples revealed green emissions were relating to transitions between the neutral Ga substitution donor (Ga Zn ) and oxygen interstitial acceptor (O i ). Multi-Gaussian fitting showed green emissions consisted of two adjacent bands located at 2.50 eV and 2.65 eV, which corresponded to G a Zn 0 + V Zn − → G a Zn + + V Zn 2 − and Ga Zn 0 + O i 0 → Ga Zn + + O i − transitions, respectively. Concentrations of O i 0 and V Zn − were increased with the increasing PO 2 is the reason why green emissions were influenced by PO 2 .