Green electroluminescence from a Tb-doped AlN thin-film device on Si

Green photoluminescence and electroluminescence (EL) from Tb implanted AlN films have been observed at room temperature. The AlN films of 180 nm thickness were grown on n-type Si(111) by metalorganic chemical vapor deposition. X-ray diffraction shows that the AlN is polycrystalline. The AlN films were doped by ion implantation of Tb to a peak concentration of 1 at. %. A postimplantation annealing step was required to obtain optically active Tb ions. A dc EL device was fabricated using a transparent ZnO:Al top electrode. The strong room-temperature green light emission was observable with the naked eye. It was obtained with a drive current density of 2–70 mA/cm2 at a drive voltage of 70–100 V. The emission lines between 490 and 650 nm originate from Tb3+ transitions from the D45 level to ground state multiplets. The observed luminescence lifetimes are approximately 0.5 ms.