Díaz-Guerra Viejo, CarlosPiqueras De Noriega, Francisco JavierVolciuc, O.Popa, V.Tiginyanu, I. M.2023-06-202023-06-202006-07-150021-897910.1063/1.2214210https://hdl.handle.net/20.500.14352/51108© 2006 American Institute of Physics. This work has been supported by MEC through Project No. MAT2003-00455, CAM through Project GR/MAT 630-04, U.S. Civilian Research and Development Foundation under Grant Nos. MR2-995 and MOR2-1033-CH-03, as well as by the Supreme Council for Research and Technological Development of Moldova.Cathodoluminescence (CL) microscopy and spectroscopy have been used to investigate the optical properties of GaN microstructures patterned by Ar+ ion irradiation and subsequent photoelectrochemical (PEC) etching. Monochromatic CL images and CL spectra reveal an enhancement of several defect-related emission bands in a 10 mu m wide area around each microstructure. In addition, columnar nanostructures and nanoetch pits were found in the PEC etched areas. CL emission of the nanocolumns is dominated by free electron to acceptor transitions, while excitonic luminescence prevails in the rest of the etched GaN layers. Investigation of the sidewalls of the microstructures reveals that a CL emission band centered at about 3.41 eV, attributed to excitons bound to structural defects, is effectively suppressed after PEC etching only in the observed nanocolumns.engjournal articlehttp://dx.doi.org/10.1063/1.2214210http://scitation.aip.orgopen access538.9Molecular-Beam EpitaxyDamage-Induced MaskingVapor-Phase-EpitaxyLuminescence PropertiesFreestanding GanPhotoluminescenceDefectsGalliumIlluminationTransitionsFísica de materiales