Photoluminescence and damage recovery studies in Fe-implanted ZnO single crystals

We report Fe3+-related emission in ion-implanted ZnO single crystals. Iron. ions were implanted at room temperature with 100 keV and a fluence of 1 x 10(16) Fe+/cm(2), and were submitted to annealing treatments in vacuum and in air. After implantation, the damage raises the minimum yield (chi(min)) from 2% to 50%. Annealing in an oxidizing atmosphere leads to a reduction of. the implantation damage, which is fully recovered after annealing at 1050degreesC with a chi(min)similar to3% in the implanted region. With extrinsic excitation, red Fe-related emission is observed at low temperatures. The intensity. is dependent, on the annealing conditions. For. samples annealed in air, the luminescence can be detected up to 120 K. When a comparison is,,made between unimplanted and post-implanted annealed samples, noticeable changes, on near-band-edge and deep-level photoluminescence spectra are observed, A thermally populated structured green emission could be observed in the sample annealed in air, as shown by the temperature-dependent photoluminescence excitation studies. (C) 2003 American Institute of Physics.