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Europium activated yttrium oxide (Eu:Y2O3) phosphor films have been grown in situ on (100) bare and diamond-coated silicon substrates using a pulsed laser deposition technique. Diamond-coated silicon substrates were prepared using hot filament chemical vapor deposition of diamond onto silicon. Photoluminescence brightness from Eu:Y2O3 films grown at 700 °C on diamond-coated silicon substrates was about twice that of films on bare silicon, and reached 80% of the brightness of powders. The higher brightness from Eu:Y2O3 film on diamond-coated silicon substrates is attributed to reduced internal reflections from the Eu:Y2O3 film surface, which results from the roughness of the diamond layer.

This letter investigates the role of postdeposition oxygen treatments upon their luminescent properties by synthesizing Eu:Y2O3 films by pulsed laser deposition under different conditions and subjecting them to various postdeposition oxygen treatments. Our results have shown that Eu:Y2O3 films grown in 300 mTorr oxygen ambient and cooled in vacuum (10−6 Torr) after the termination of growth exhibit better photoluminescent and cathodoluminescent brightness than those grown in (i) vacuum and cooled in vacuum and (ii) 300 mTorr oxygen and cooled in 2 Torr oxygen. Two possible mechanisms have been proposed to explain these results.

We report the epitaxial growth of europium-activated yttrium oxide (Y2O3:Eu) (001) thin films on LaAlO3 (001) using laser ablation deposition at a substrate temperature of 775 °C and 10 Hz pulse repetition rate. The orientation relationship between the films and the substrates is [110]Y2O3∥[100]LaAlO3 and [−110]Y2O3∥[010]LaAlO3 which results in a lattice mismatch of only 0.8%. Transmission electron microscopy (TEM) of the films reveals the single crystalline Y2O3:Eu thin film to contain small pores. Scanning transmission electron microscopy (STEM) imaging of the films shows the substrate always terminates with the Al sublattice. Moreover, the STEM reveals that no precipitates of Eu had formed in the films.

We report the observation of porous structures in laser-ablation-deposited Y2O3:Eu thin films and their correlation with luminescent properties by a combination of transmission electron microscopy and Z-contrast scanning transmission electron microscopy (Z-STEM). Depending on growth conditions, a large density of voids is incorporated into the films, which leads to a much increased surface area. Cathodoluminescence imaging in the STEM directly reveals a 5 nm “dead layer” around each void, which is responsible for the observed reduction in luminescence efficiency.