Intersection Nodes of Basal Screw Dislocations as Luminous Quantum Dots in GaN

Abstract

For the first time, in situ direct cathodoluminescence observation of the formation of luminous dots with a particular spectral luminescence band at the intersection nodes of straight basal screw dislocations in GaN is reported. The formation of the nodes that luminesced at around 3.3 eV proceeded under electron beam excitation as a result of interaction between straight screw dislocations, which possessed an own luminescence band at 3.1–3.2 eV. Possible configurations of the structure of dislocation nodes for the perfect and for the dissociated dislocations are presented and discussed, together with the properties of intersection‐related luminescence (IRL). The origin of IRL is tentatively ascribed to the optical transition between electronic states of quantum dots formed by extended dislocation nodes, consisting of I2 stacking faults bounded by 30° partial dislocations.