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The crystal structure of the triclinic form of lead phthalocyanine has been determined. The crystal data are: C32HI6NsPb, M r = 719.7, Pi, a = 13.123 (7) The final R value is 0.059 for 7683 reflections. Two independent molecular columns exist in this crystal, but they have almost equivalent structures. The molecules are considerably distorted from C4v symmetry. The central Pb atom significantly deviates from the convex side of the phthalocyanine skeleton, and this deviation is larger than that in the monoclinic form of lead phthalocyanine. Molecules are stacked along the a axis and oriented so that their convex sides alternate. They are considerably inclined with respect to the stacking axis.

We investigated the propagation of the threading dislocations in the GaN layer grown by facet-controlled epitaxial lateral overgrowth (FACELO). The mixed-type dislocations were bent toward the mask areas and they were terminated at the voids on the SiO2 masks. On the other hand, the pure edge dislocations were bent in the direction of the mask stripe. No dislocations originating from the GaN/sapphire interface propagated to the surface. As a result, it was confirmed that a large reduction of dislocation density was achieved. Therefore, FACELO seems to be a promising technique for the realization of a GaN wafer of low dislocation density.