LUMINESCENCE QUENCHING IN ERBIUM-DOPED HYDROGENATED AMORPHOUS-SILICON

Hydrogenated amorphous silicon thin films are doped with erbium by ion implantation. Room-temperature photoluminescence at 1.54 mu m, due to an intra-4f transition in Er4+, is observed after thermal annealing a t 300-400 degrees C. Excitation of Er3+ is shown to be mediated by pho tocarriers. The Er3+ luminescence intensity is quenched by a factor of 15 as the temperature is raised from 10 K to room temperature. Codopi ng with oxygen (1 at. %) reduces the luminescence quenching to a facto r of 7. The quenching is well correlated with a decrease in luminescen ce lifetime, indicating that nonradiative decay of excited Er3+ is the dominant quenching mechanism as the temperature is increased. (C) 199 6 American Institute of Physics.