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.