Formation of Ti3+ in sapphire by co-implantation of Ti and O ions

We have demonstrated that co-implantation of Ti and O ions into c-axis orie nted alpha-Al2O3 substrates followed by thermal annealing can substantially increase the fraction of Ti ions present in the optically active 3+ oxidat ion state. Evidence for the presence of Ti3+ is given by the observation of strong luminescence over the wavelength range similar to 600-900 nm under Ar laser excitation and by the presence of the characteristic absorption ba nd at similar to 450-550 nm. We have studied the luminescence intensity as a function of implantation and annealing parameters and have found that the re is a strong dependence on the ratio of implanted Ti and O and on the ann ealing temperature. (C) 2000 American Institute of Physics. [S0003-6951(00) 01604-1].