AbstractSpherical, sub‐micrometer Y2O3:Eu and Cubic (Y2‐(x+y)Gdx)O3:Euy3+ (where x = 0.02 to 0.40, y = 0.04) phosphor particles have been synthesized by a novel solution method. These phosphor particles will be ideal for FED devices as they can densely close‐pack on screens and they display high efficiency under low voltage electron beam excitation. It is shown herein that spherical phosphor powder particles can be useful in voltage ranges up to 5000 V and it is also shown in this work that cubic‐Y2O3:Eu particles (ca. 300 nm) perform well at such voltages.