Enhanced excitation efficiency of Eu ions in Eu-doped GaN/AlGaN multiple quantum well structures grown by organometallic vapor phase epitaxy

We have grown Eu-doped GaN (GaN:Eu)/AlGaN multiple quantum well (MQW:Eu) structures by organometallic vapor phase epitaxy and investigated their Eu luminescence properties. The MQW:Eu structures exhibited enhancement of Eu photoluminescence (PL) intensity with an integrated intensity which was three times higher than that of conventional GaN:Eu structures. PL and time-resolved PL measurements suggest that this enhancement is due to the improvement of the excitation efficiency of Eu ions in the MQW:Eu structure. Following these results, we have successfully fabricated a light-emitting diode based on the MQW:Eu structures, which demonstrated an improved output power efficiency of red light. •Eu doped GaN quantum well structures were grown by OMVPE.•The luminescence properties of these structures were studied.•Both electrical and optical excitations of Eu ions are possible.•Both excitation methods show an increased efficiency.•The mechanism behind the increased efficiency is discussed.