Hydrogenated amorphous silicon thin films are doped with erbium by ion
implantation. Room-temperature photoluminescence al 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.