Morphology and cathodoluminescence of Li-doped Gd2O3:Eu3+, a red phosphor operating at low voltages

A red phosphor, Li-doped Gd2O3:Eu3+ with high cathodoluminescent brightness was developed. In contrast to Gd2O3:Eu3+ which showed an irregular shape of agglomerated fine particles (the mean particle size <0.5 μm), the morphology of Li doped Gd2O3:Eu3+ crystals was quite regular and pseudospherical (the mean particle size ≈2 μm). In particular, the incorporation of Li+ ions into Gd2O3 lattice could induce a remarkable increase of cathodoluminescence efficiency at low voltages (500 V–1 kV). The highest emission intensity was observed with Gd1.84Li0.08Eu0.08O3−δ, whose brightness at 500 V was increased by a factor of 1.8 in comparison with that of commercial Y2O3:Eu3+. This phosphor may be an application to the field emission display operating at low voltages.