FABRICATION OF Y3AL5O12-EU THIN-FILMS AND POWDERS FOR FIELD-EMISSION DISPLAY APPLICATIONS

Thin films of Y3Al5O12:Eu (YAG) were spin coated on different substrat es from sols. The precursor solution was made from organic precursors by combining stoichiometric ratios of Y(III) iso-propoxide, Al(tri Sec -butoxide) and Eu(III) acetyl acetonate. Sol-gel derived thin films an d powders are non-crystalline. Powder samples calcined at 650 degrees C for 5 h show the characteristic X-ray diffraction pattern for the YA G phase. Similarly, the thin film samples annealed at 600 degrees C fo r 5 h also show YAG phase in the XRD. The emission spectra were measur ed for both the powder and thin-film samples. Scanning electron micros copy for the powder samples show that the particles are reasonably cry stallized with a particle size of 5 mu m. The spectral response and ou t gassing characteristic of the new, low voltage YAG thin films mainly used for application in the field emission flat panel displays are al so measured. The cathodoluminescent materials were tested with electro n beam excitation at currents of up to 50 mu A within the 3000-8000 V range (medium voltage range). The spectral coordinates with minimal op timization as compared with industrially manufactured P22 phosphors at low voltage operation are reasonable.