High-resolution X-ray diffraction was used to analyze the type and density of threading dislocations in (00•1)-oriented GaN epitaxial films. Photoluminescence and carrier mobilities of the films were measured at room temperature. The intensities of both the band-edge (3.42eV) peak and yellow luminescence were strongly related to the threading dislocation density of the films. But different types of dislocation had different relationships to the intensities of photoluminescence and yellow luminescence. A fundamental correlation was found not only between the interaction of edge- and screw-type dislocations and the carrier mobility, but also between the interaction and the intensities of both the band-edge peak and the yellow luminescence.

Influence of Different Types of Threading Dislocations on Carrier Mobility and Photoluminescence in Epitaxial GaN. J.Y.Shi, L.P.Yu, Y.Z.Wang, G.Y.Zhang, H.Zhang: Applied Physics Letters, 2002, 80[13], 2293-5