[22a-C200-1~10] 15.4 III-V-group nitride crystals

[22a-C200-5] Improved luminescence efficiency of Eu,O-codoped GaN due to a reconfiguration of luminescent sites caused by a post-growth annealing

〇Takenori Iwaya¹, Shuhei Ichikawa^1,2, Dolf Timmerman¹, Jun Tatebayashi¹, Yasufumi Fujiwara¹ (1.Osaka Univ., 2.Research Center for UHVEM, Osaka Univ.)

Keywords:GaN:Eu, red light emitting diode

We have realized GaN-based red light emitting diodes using Eu,O-codoped GaN (GaN:Eu,O) active layers grown by the organometallic vapor phase epitaxy method. Growth at a relatively low temperature (~960°C) enables a high crystal quality growth of GaN:Eu,O layers, but also elevates Eu-clustering due to the low diffusion coefficient, which results in the formation of a large number of inefficient luminescent sites. In this report, for the formation of efficient luminescent sites, we perform a post-growth thermal annealing to promote Eu atomic diffusion and report on the improved luminescent efficiency of GaN:Eu,O layers.