Low-voltage cathodoluminescence property of Li-doped Gd2-xYxO3:Eu3+

Cathodoluminescent (CL) spectra of Li-doped Gd2-xYxO3:Eu3+ solid-solution (0.0≤x≤0.8) were investigated at low voltages (300 V-1 kV). The CL intensity is maximum for the composition of x=0.2 and gradually reduces with increasing the amount of substituted Y content. In particular, small (∼100 nm) particles of Li-doped Gd1.8Y0.2O3:Eu3+ are obtained by firing the citrate precursors at only 650 deg. C for 18 h. Relative red-emission intensity at 300 V of this phosphor is close to 180% in comparison with that of commercial red phosphor Y2O3:Eu3+. An increase of firing temperature to 900 deg. C results in 400-600 nm sized spherical particles. At low voltages (300-800 V), the CL emission of 100 nm sized particles is much stronger than that of 400-600 nm sized ones. In contrast, the larger particles exhibit the higher CL emission intensity at high voltages (1-10 kV). Taking into consideration small spherical morphology and effective CL emission, Li-doped Gd1.8Y0.2O3:Eu3+ appears to be an efficient phosphor material for low voltage field emission display