Selective deposition and luminescence characterization of Eu-doped Y₂O₃ nanoparticles by microwave plasma synthesis

Nanosize phosphor particles of Eu-doped Y₂O₃ were synthesized at room temperature by an organometallic vapor-phase microwave plasma-synthesis technique. These particles were selectively deposited downstream of the plasma reaction region to form thin layers on biased regions of a substrate. Particles were characterized using x-ray diffraction and transmission electron microscopy. The morphologies of the thin phosphor layers were studied using field-emission scanning electron microscopy. Results indicate that the particles form a fibrous structure with good selectivity for thicknesses less than 100 nm. The nanoparticle-phosphor optical characteristics were analyzed using absorption and photoluminescence spectroscopy. These results indicate that the particles have absorption and luminescence spectra similar to the bulk. This study demonstrates that the microwave plasma-synthesis technique may provide an effective method for producing phosphor screens that meet many of the needs of advanced cathodoluminescent low-voltage devices.