Cathodoluminescence characteristics of particles and film of (Y, Zn)2O3:Eu phosphor prepared by spray pyrolysis

Eu-doped Y2O3 particles with spherical shape and fine size were prepared by spray pyrolysis. The cathodoluminescence of Y2O3:Eu3+ powder was optimized by substituting small amount of zinc atoms in place of yttrium sites. As a result, the optimized (Y, Zn)2O3:Eu3+ phosphor showed 60% improved cathodoluminescence compared with Y2O3:Eu3+ particles. The prepared (Y, Zn)2O3:Eu3+ phosphor had spherical shape and 0.726 μm in mean size. Using these particles, the thickness of the phosphor film was controlled by varying the phosphor loading. The brightness and luminous efficiency of phosphor films prepared were monitored with varying the accelerating voltage ranges from 4 to 14 kV. The dependency of the luminous efficiency on the accelerating voltage was very sensitive to the phosphor loading. As increasing the accelerating voltage from 4 to 14 kV, the brightness of phosphor films prepared was monotonically increased from 200 to 1085 cd/cm2, but the saturation in the luminous efficiency appeared at 10 kV. The highest efficiency was achieved when the number of phosphor-particles layer was about 3. More details about the luminous efficiency and brightness were discussed with changing the phosphor loading.