Green emission from Er-doped GaN grown by molecular beam epitaxy on Si substrates

Visible light emission has been obtained from Er-doped alpha-GaN thin films grown on Si(111). The GaN was grown by molecular beam epitaxy using solid sources (for Ga and Er) and a plasma gas source for N-2. Photoexcitation with a He-Cd laser resulted in strong green emission from two narrow green lines at 537 and 558 nm identified as Er transitions from the H-2(11/2) and S-4(3/2) levels to the I-4(15/2) ground state. X-ray diffraction shows the GaN:Er to be a wurtzitic single crystal film. The growth temperature is seen to have a strong effect on the GaN:Er surface morphology. (C) 1998 American Institute of Physics. [S0003-6951(98)02641-2].