Abstract: Phosphor compositions are prepared by treating metal oxides or mixed-metal oxides with refractory metals to form cathodoluminescent phosphors stimulatable by electrons of very low energy. The phosphors comprise 90% to 100% of a mixed metal oxide Mx,TyOz (where M is a metal selected from Zn, Sn, In, Cu, and combinations thereof; T is a refractory metal selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and combinations thereof; and O is Oxygen, x, y, and z being chosen such that z is at most stoichiometric for MxTyOz) and 0% to 10% of a dopant comprising a substance selected from a rare earth element of the lanthanide series, Mn, Cr, and combinations thereof, or stoichiometrically excess Zn, Cu, Sn, or In. A blue-light-emitting phosphor based on ZnO treated with Ta2O5 or Ta to form Ta2Zn3O8 is characterized by CIE 1931 chromaticity values x and y, where x is between about 0.14 and 0.20 and y is between about 0.05 and 0.15.