Figure 5

Cross-sectional TEM images of regrown AlGaN/AlN MQWS on mixed-polarity AlN nanorods. (a) STEM images of nanorods. (b) Magnified image of area in red dashed box in (a); annihilation of dislocations within domain boundaries is observed. (c) ID boundaries are observed along (0002) g vector. (d) TEM image along (1–100) g vector; edge-type dislocations are gathered and finally terminated inside neighboring N-polar AlN domains.