Characterization of photoluminescent (Y1-xEux)(2)O-3 thin films prepared by metallorganic chemical vapor deposition

The purpose of this study was to identify and correlate the microstructural and luminescence properties of europium-doped Y2O3 (Y1-xEux)(2)O-3 thin fi lms deposited by metallorganic chemical vapor deposition (MOCVD), as a func tion of deposition time and temperature. The influence of deposition parame ters on the crystallite size and microstructural morphology were examined, as well as the influence of these parameters on the photoluminescence emiss ion spectra. (Y1-xEux)(2)O-3 thin films were deposited onto (111) silicon a nd (001) sapphire substrates by MOCVD. The films were grown by reacting ytt rium and europium tris(2,2,6,6-tetramethyl-3,5-heptanedionate) precursors w ith an oxygen atmosphere at low pressures (5 torr (1.7 x 10(3) Pa)) and low substrate temperatures (500 degrees-700 degrees C). The films deposited at 500 degrees C were smooth and composed of nanocrystalline regions of cubic Y2O3, grown in a textured [100] or [110] orientation to the substrate surf ace. Films deposited at 600 degrees C developed, with increasing deposition time, from a flat, nanocrystalline morphology into a platelike growth morp hology with [111] orientation. Monoclinic (Y1-x Eu-x)(2)O-3 was observed in the photoluminescence emission spectra for all deposition temperatures. Th e increase in photoluminescence emission intensity with increasing postdepo sition annealing temperature was attributed to the surface/grain boundary a rea-reduction effect.