Crystallographic Properties of Bulk GaN Crystals Grown at High Pressure
M. Leszczyński, I. Grzegory, M. Bockowski, J. Jun, S. Porowski
High Pressure Research Center, Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warszawa, Poland

J. Jasiński and J.M. Baranowski
Institute of Experimental Physics, Warsaw University, Hoża 69, 00-681 Warszawa, Poland
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Gallium nitride bulk crystals grown at about 15 kbar and 1500 K have been examined by using the high resolution X-ray diffractometry. An anal­ysis of a set of the rocking curves of various Bragg reflections enabled us to estimate a dislocation density. For the crystals of dimensions lower than about 1 mm it is lower than 10-5 cm-2. For bigger samples the crystallo­graphic quality worsens. With an application of the reciprocal lattice map­ping we could distinguish between internal strains and mosaicity which are both present in these crystals The results for the bulk crystals are compared with those for epitaxial layers.
DOI: 10.12693/APhysPolA.88.799
PACS numbers: 61.50.Cj, 61.72.Dd