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 μm, due to an intra-4f transition in Er4+, is observed after thermal annealing at 300-400 °C. Excitation of Er3+ is shown to be mediated by photocarriers. The Er3+ luminescence intensity is quenched by a factor of 15 as the temperature is raised from 10 K to room temperature. Codoping with oxygen (1 at. %) reduces the luminescence quenching to a factor of 7. The quenching is well correlated with a decrease in luminescence lifetime, indicating that nonradiative decay of excited Er3+ is the dominant quenching mechanism as the temperature is increased.