Thulium-doped yttrium oxide (Y2O3:Tm) thin films were grown on amorphous quartz and indium-tin oxide glass substrates employing an electron-beam evaporation technique. Structural characterization was carried out at various substrate and annealing temperatures. Y2O3:Tm was evaluated as a blue-emitting phosphor for field emission display based on its cathode-luminescent spectra, chromaticity, and brightness at low-voltage excitation (<5 keV). Sharp emission was observed from thulium at 454 nm. The cathode luminance of the thin films was assessed with respect to substrates and annealing temperatures. The result shows that Y2O3:Tm grown on indium-tin oxide glass at 500 degrees C followed with annealing at 800 degrees C has better luminescent properties as compared to amorphous quartz.