Correlation of structure and intrinsic luminescence of freshly introduced dislocations in GaN revealed by SEM and TEM

Dislocation structure and cathodoluminescence (CL) of locally plastically deformed n-GaN is investigated in transmission electron microscope (TEM) and in scanning electron microscope (SEM). Multiple dense indentations of the samples with subsequent TEM foil preparation enables to study the same dislocation-rich region of the specimen with both TEM and CL-SEM and to establish direct correlation between the types of dislocations and their luminescent properties. It is shown that only straight segments of a-screw dislocations possess intrinsic luminescent band at 3.12 eV at room temperature confirming previous conclusion made from independent SEM and TEM results.