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 mm, due to an intra-4ƒ 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 (I 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.