• Zhang, Z.
• Lorenz, K.
• Sequeira, Miguel C.
• Alves, E.
• Felemban, Tahani
• Venkatesh, S.

Abstract

Gd-doped ZnO thin films were prepared using pulsed laser deposition at different oxygen pressures and varied Gd concentrations. The effects of oxygen deficiency-related defects on the Gd incorporation, optical and structural properties, were explored by studying the impact of oxygen pressure during deposition and post-growth thermal annealing in vacuum. Rutherford Backscattering Spectrometry revealed that the Gd concentration increases with increasing oxygen pressure for samples grown with the same Gd-doped ZnO target. Unexpectedly, the c-lattice parameter of the samples tends to decrease with increasing Gd concentration, suggesting that Gd-defect complexes play an important role in the structural properties. Using low-temperature photoluminescence(PL), Raman measurements and density functional theory calculations, we identified oxygen vacancies as the dominant intrinsic point defects. PL spectra show a defect band related to oxygen vacancies for samples grown at oxygen deficiency.

Topics

• density
• photoluminescence
• theory
• thin film
• Oxygen
• density functional theory
• annealing
• pulsed laser deposition
• spectrometry
• Rutherford backscattering spectrometry
• point defect