Rare earth doping of III-V nitride semiconductors

Optoelectronic materials doped with rare earth atoms are receiving widespread attention due to their impact on optical communication systems operating at 1.54 mu m and 1.3 mu m. Optical amplifiers based on Er-doped fibers have demonstrated major improvements in link distance, data rates, and reduced needs for signal regeneration. The intra-subshell transitions of 4f electrons in rare earth ions lead to narrow absorption peaks in the ultra-violet, visible, and near-infrared regions of the electromagnetic spectrum. Since it appears that the intensity of the room temperature light emission depends upon the energy bandgap of the host material, wide gap semiconductors may prove to be the best materials for device applications. Wide gap semiconductors, such as the III-V nitrides, doped with rare earth atoms offer the prospect of very stable, temperature-insensitive, light emitting diodes and laser diodes emitting at wavelengths from the visible to the near infrared. This paper presents a review of the rare earth doping and the luminescence characteristics of m-V nitride semiconductors. Aspects of Er atom incorporation in the crystal host, photoluminescence properties, and prototype electroluminescent devices based on III-V nitrides are addressed.