Feneberg, MartinRomero, FátimaGoldhahn, RüdigerWernicke, TimReich, ChristophStellmach, JoachimMehnke, FrankKnauer, ArneWeyers, MarkusKneissl, Michael2021-11-122021-11-122021-05-170003-6951https://depositonce.tu-berlin.de/handle/11303/13879http://dx.doi.org/10.14279/depositonce-12652Light emitting diode structures emitting in the ultraviolet spectral range are investigated. The samples exhibit defect luminescence bands. Synchrotron-based photoluminescence excitation spectroscopy of the complicated multi-layer stacks is employed to assign the origin of the observed defect luminescence to certain layers. In the case of quantum well structures emitting at 320 and 290 nm, the n-type contact AlGaN:Si layer is found to be the origin of defect luminescence bands between 2.65 and 2.8 eV. For 230 nm emitters without such n-type contact layer, the origin of a defect double structure at 2.8 and 3.6 eV can be assigned to the quantum wells.en530 Physikquantum wellsphotoluminescence spectroscopyheterostructuresphotoluminescence excitation spectroscopylight emitting diodessemiconductorssynchrotron radiationArticle1077-3118