Zaldivar, M.H.Fernández Sánchez, PalomaPiqueras De Noriega, Francisco Javier2023-06-202023-06-201998-01-010021-897910.1063/1.366661https://hdl.handle.net/20.500.14352/59162© © 1998. All rights reserved. This wirk was supported by DGICYT (Proyect No. PB-1256). M.H.Z. thanks AECI for a research grand.Cathodoluminescence (CL) in the scanning electron microscope is used to investigate the nature of defects responsible for the luminescence associated with round and hexagonal-like topographic features of GaN:Si films. Round hillocks of the size of a few microns, which sometimes have a nanopipe related central hole, do not influence the luminescence emission of the film. Hillocks with sizes of several tens of microns show a marked CL contrast at the center and at the border. The origin of the observed contrast is attributed to a growth induced inhomogeneous distribution of point defects and impurities. Radiation with the electron beam of the scanning microscope causes a decrease of the CL intensity without spectral changes.engjournal articlehttp://dx.doi.org/10.1063/1.366661http://scitation.aip.orgopen access538.9Física de materiales