Visible and infrared rare-earth-activated electroluminescence from indium tin oxide Schottky diodes to GaN : Er on Si

Visible and infrared rare-earth-activated electroluminescence (EL) has been obtained from Schottky barrier diodes consisting of indium tin oxide (ITO) contacts on an Er-doped GaN layer grown on Si. The GaN was grown by molecu lar beam epitaxy on Si substrates using solid sources for Ga, Mg, and Er an d a plasma source for N-2. RF-sputtered ITO was used for both diode electro des. The EL spectrum shows two peaks at 537 and 558 nm along with several p eaks clustered around 1550 nm. These emission lines correspond to atomic Er transitions to the I-4(15/2) ground level and have narrow linewidths. The optical power varies linearly with reverse bias current. The external quant um and power efficiencies of GaN:Er visible light-emitting diodes have been measured, with values of 0.026% and 0.001%, respectively. Significantly hi gher performance is expected from improvements in the growth process, devic e design, and packaging. (C) 1999 American Institute of Physics. [S0003-695 1(99)01002-5].