Abstract: Bulk mono-crystalline gallium-containing nitride, grown on the seed at least in the direction essentially perpendicular to the direction of the seed growth, essentially without propagation of crystalline defects as present in the seed, having the dislocation density not exceeding 104/cm2 and considerably lower compared to the dislocation density of the seed, and having a large curvature radius of the crystalline lattice, preferably longer than 15 m, more preferably longer than 30 m, and most preferably of about 70 m, considerably longer than the curvature radius of the crystalline lattice of the seed.