Corfdir, PierreLefebvre, PierreLevrat, JacquesDussaigne, AmélieGanière, Jean-DanielMartin, DenisRistic, JelenaZhu, TiankaiGrandjean, NicolasDeveaud-Plédran, Benoît2009-03-012009-03-012009-03-01200910.1063/1.3075596https://infoscience.epfl.ch/handle/20.500.14299/35706WOS:000263803300002We present a detailed study of the luminescence at 3.42 eV usually observed in a-plane epitaxial lateral overgrowth (ELO) GaN grown by hydride vapor phase epitaxy on r-plane sapphire. This band is related to radiative recombination of excitons in a commonly encountered extended defect of a-plane GaN: I-1 basal stacking fault. Cathodoluminescence measurements show that these stacking faults are essentially located in the windows and the N-face wings of the ELO-GaN and that they can appear isolated as well as organized into bundles. Time-integrated and time-resolved photoluminescence, supported by a qualitative model, evidence not only the efficient trapping of free excitons (FXs) by basal plane stacking faults but also some localization inside I-1 stacking faults themselves. Measurements at room temperature show that FXs recombine efficiently with rather long luminescence decay times (360 ps), comparable to those encountered in high-quality GaN epilayers. We discuss the possible role of I-1 stacking faults in the overall recombination mechanism of excitons.cathodoluminescenceexcitonsgallium compoundsIII-V semiconductorsphotoluminescencesapphiresemiconductor epitaxial layerssemiconductor growthstacking faultstime resolved spectravapour phase epitaxial growthwide band gap semiconductorsMultiple-Quantum WellsOptical-PropertiesHeterostructuresSemiconductorsLuminescenceEmissionstext::journal::journal article::research article