Resonant excitation of Er ion luminescence in a nanocrystalline silicon matrix

The luminescence of amorphous silicon layers either implanted with Er or co-implanted with Er and O has been studied by photoluminescence (PL) and cathodoluminescence (CL) in the scanning electron microscope. Annealing in nitrogen causes the formation of oxide species and Er-Si complexes or precipitates as well a spectral changes in the visible and infrared ranges. The main CL emission takes place in the visible range while PL spectra reveal intense visible and infrared emission. CL spectra show blue-violet, or green, emission bands whose relative intensities depend on the post-implantation annealing temperature. The PL spectra show a blue-violet band with a series of lines in the violet region related to phonon assisted transitions as well as different emission bands in the range 1200-1500 nm. The influence of the annealing-induced structural changes on the observed spectra is discussed