Eu luminescence center created by Mg codoping in Eu-doped GaN

We investigated the photoluminescence properties of Eu,Mg-codoped GaN grown by organometallic vapor phase epitaxy. Some emission due to intra-4f shell transition of 5D0-7F2 in Eu3+ ions in a center with Eu and Mg was observed together with typical Eu emission. The peak intensity of the Eu-Mg emission was about five times higher than that of the typical Eu emission. The Eu-Mg emission exhibited a maximum at around 180 K, while the typical Eu emission intensity decreased monotonically with increasing temperature. It was found that only one type of Eu-Mg center contributed to the enhanced intensity up to 180 K.