2014 年 42 巻 3 号 p. 211-
A new type of red light-emitting diode (LED) has been developed using Eu-doped GaN (GaN:Eu) as an active layer. The LED can emit characteristic emission due to the intra-4f shell transitions in Eu3+ ions doped in GaN at room temperature. By optimizing organometallic vapor phase epitaxial growth conditions of the GaN:Eu and the device structure, the output light power has increased signifi cantly up to sub-milliwatts. For the more improved output light power, energy-transfer mechanism from the GaN host to Eu ions and effects of impurity codoping are also discussed in GaN:Eu.