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°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°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.