Inhomogeneous broadening of the Ce3+ luminescence in CaYAlO4

Five absorption bands with peaks at less than or equal to 210 nm, 246 nm, 284 nm, 296 nm, and 368 nm were observed at room temperature for Ce-doped CaYAlO4 (CYA) crystals grown in a reducing atmosphere. Excitation at wavelengths below similar to 400 nn of Ce:CYA crystals produces a broad luminescence band with a peak at similar to 485 nm. The excitation spectrum of the luminescence detected at a fixed wavelength of 485 nm is very similar to the absorption spectrum. The ultraviolet absorption and visible luminescence are due to the 4f(1) <-> 5d(1) transitions of Ce3+ ions in CYA. The linear dependence of the luminescence peak energy on the excitation energy shows that the luminescence is inhomogeneously broadened by a random distribution of Ca2+ and Y3+ ions in the disordered CYA lattice.