Figure 1. Plan-view aberration-corrected HAADF-STEM image of the AlGaN sample, showing the core structure of an edge-type dislocation (5/7-atom ring)(a,d,g), an undissociated mixed-type dislocation (double 5/6-atom ring)(b,e,h) and a dissociated mixed-type dislocation (7/4/8/4/9-atom ring)(c,f,i). Raw unfiltered images (a-c), and ABSF-filtered (average background subtraction filter) (d-f) with atomic columns identified to guide the eye (g-i).

Figure 2. (a) Unfiltered HAADF-STEM image of an undissociated mixed-type dislocation. (b) ABSF-filtered image of (a) with geometric phase analysis overlay showing the x-x strain component (x-axis parallel to [11-20]). (c) EDX line scan showing the composition of Al, Ga, and N along the line depicted in (b) (with a ca. 1 nm analysis width).

Figure 3. (a) AFM, (b) CL integrated intensity, and (c) CL peak emission energy of the same region in the AlGaN sample.

Figure 4. (a) AFM, (b) CL integrated intensity, and (c) CL peak emission energy of the same region in the InGaN sample.

Figure 5. Simulation of the emission energy shift in the vicinity of an edge-type dislocation.