Low-pressure metalorganic chemical vapor deposition of photoluminescent Eu-doped Y₂O₃ films

We have produced thin photoluminescent films of Eu-doped Y₂O₃ (Y₂O₃: Eu) by low-pressure metalorganic chemical vapor deposition (MOCVD). Yttrium and europium β-diketonate precursors are thermally decomposed in a hot-walled MOCVD reactor in the presence of oxygen at a total reactor pressure of 1 Torr. The films are microcrystalline and photoluminescent as-deposited and contain <1 at.% of carbon contamination. Subsequent annealing at 1200°C in air enhances and stabilizes the luminescence. We have measured the photoluminescent lifetimes of the MOCVD films as a function of temperature for the Eu⁺³⁵D₁ ⇉ ⁷F₁ and ⁵D₀ ⇉ ⁷F₂ transitions using excimer laser excitation at 248 nm. We present a kinetic model which can account for the observed emission lifetimes from 20–1000°C.