Control of GaN facet structures through Eu doping toward achieving semipolar {11¯01} and {22¯01} InGaN/GaN quantum wells

We have grown Eu-doped GaN on striped GaN facet structures with {11¯01} faces using a selective-area-growth technique. It was found that the orientation of the Eu-doped GaN facets depends on the Eu doping conditions. Semipolar {nn¯01} (n = 2, 3) facets, which are difficult to form using conventional undoped GaN, can be obtained by changing the growth temperature and the amount of the supplied Eu precursor. InGaN/GaN multiple quantum wells (MQWs) were also fabricated on the Eu-doped semipolar facets, and their structural and luminescence properties were investigated. The MQWs fabricated on the Eu-doped semipolar {22¯01} facets have a photoluminescence decay time of 112–314 ps, which is 10 times shorter than those of conventional (0001) QWs. These results show that the Eu doping of GaN is a promising means of obtaining various semipolar facets, which can contribute to improve the radiative recombination probability.