Photoluminescence Properties of Eu-Doped ZnO Grown by Sputtering-Assisted Metalorganic Chemical Vapor Deposition

Abstract

Photoluminescence (PL) properties of Eu-doped ZnO (ZnO:Eu) grown by a sputtering-assisted metalorganic chemical vapor deposition technique were investigated. In PL measurements at 300K, the samples annealed at 600°C for 30min showed clear red-emission lines due to the intra-4f shell transition of ⁵D₀→⁷F_J (J = 2, 3) in Eu³⁺. In photoluminescence excitation (PLE) spectra, the PL were observed under the high-energy excitation above the band-gap energy of ZnO (indirect excitation) and the low-energy excitation resonant to the energy levels of ⁷F₀-5D3 and ⁷F₀-⁵D₂ transitions in Eu³⁺ (direct excitation). These results revealed that the energy transfer from ZnO host to Eu³⁺ was accompanied under indirect excitation in ZnO:Eu.