Nanocrystalline Tm3+-doped La2O3 phosphors were prepared through a Pechini-type sol-gel process. X-ray diffraction, field-emission scanning electron microscopy, photoluminescence, and cathodoluminescence spectra were utilized to characterize the synthesized phosphors. Under the excitation of UV light (234 nm) and low-voltage electron beams (1-3 kV), the Tm3+-doped La2O3 phosphors show the characteristic emissions of Tm3+(D-1(2), (1)G(4)-F-3(4), H-3(6) transitions). The blue cathodoluminescence of the Tm3+-doped La2O3 phosphors, with a dominant wavelength of 458 nm, had better CIE coordinates (0.1457, 0.0569) and higher emission intensity than those of the commercial product [Y2SiO5:Ce3+, CIE coordinate: (0.1624, 0.0939), (product no. 1047, Nichia Kagaku Kogyo Kabushiki, Japan)]. (C) 2008 The Electrochemical Society. [DOI: 10.1149/1.2995829] All rights reserved.