Plasma-enhanced CVD (PECVD) deposited alumina (A12O3) thin films and single sapphire crystals were co-doped with both erbium and ytterbium using ion implantation. Yb3+ and Er3+ concentrations ranged from 2.4At% to 8At% and from 0.4At% to 0.8At%, respectively. The samples show relatively strong, broad, room-temperature photoluminescence (PL) at λ=11.53µm corresponding to the intra-4f transitions between the 4I13/2 (first excited) and the 4I15/2 (ground) state of Er3+. The full width at half maximum (FWHM) of the emission spectrum is as high as 67nm for the A12O3 thin films; for the sapphire crystals it is 45nm. The fluorescence lifetime of the samples has been measured to be as high as 4.2ms at 50mW laser pump power. The indirect pumping of erbium through the transfer of energy from ytterbium has been demonstrated and the PL peak intensity has been studied as a function of the Yb3+/Er3+ concentration ratio when the samples are pumped at 514nm and 850nm; the PL excitation spectrum (PL at 1.53gm as a function of pump wavelength) of an Er3+/Yb3+ co-implanted sample is also presented. Both the PL peak intensity at 1.53µm and the fluorescence lifetime have been studied as functions of annealing temperature. Luminescence spectra attributed to defects in the alumina matrix are presented for as-implanted samples and following thermal annealing.