Visible and infrared emission from GaN : Er thin films grown by sputtering

Erbium-doped films were grown on sapphire and silicon substrates by reactiv e sputtering, with different Er concentrations in the film. GaN films depos ited at 800 K were determined to be polycrystalline by x-ray diffraction an alysis, and retained their polycrystalline structure after annealing in nit rogen at 1250 K. The Er-doped films showed optical transmission beginning a t about 360 nm, and the Er dose and film purity were determined with Ruther ford backscattering spectroscopy. Photoluminescence and cathodoluminescence spectroscopy showed sharp emission lines corresponding to Er3+ intra 4f(n) shell transitions over the range from 9 - 300 K. At above-bandgap optical and electron excitation, the S-4(3/2) and F-4(9/2) transition dominate, and are superposed on the "yellow band" emission. The infrared emission line a t 1543 nm corresponding to the Er I-4(13/2) to I-4(5/2) transition is also observed.