A set of research data related to article "On Stress-Induced Polarization Effect in Ammonothermally Grown GaN Crystals"; Crystals 2022, 12, 554. The results of basic ammonothermal crystallization of gallium nitride are described. The material is mainly analyzed in terms of the formation of stress (called stress-induced polarization effect) and defects (threading dislocations) appearing due to a stress relaxation process. The set contains the data used to create Figures 1-8.
Figure 1. Scheme of an ammonothermal autoclave with a typical interior configuration and temperature-time profile of two zones in an autoclave.
Figure 2. Typical metal holders with GaN seeds for ammonothermal growth run; two levels of holders for placing inside the autoclave in the crystal growth zone; scheme of eight positions of seeds in the autoclave; average thickness of crystals grown at Positions 1-8.
Figure 3. Two native rectangular Am-GaN crystals used as seeds: sample No. 1 and sample No. 2; images in cross-polarized light.
Figure 4. Schemes of cross-section of a sample prepared for analyzing new-grown crystal and seed with an interface between them under UV illumination and new-grown crystal and seed prepared for DSE.
Figure 5. Two crystals after the growth process; images in cross-polarized light: crystal No. 1, where SIPE is well visible in the crystal grown on the seed in the [000-1] direction; part of new crystal grown in the lateral direction ([11-20]) is, in turn, SIPE-free; and crystal No. 2 - no SIPE is visible in crystal grown in the [000-1] and [11-20] directions.
Figure 6. Images under UV illumination: sample No. 1: seed, interface, and new-grown crystal; yellowish features are well visible at the interface; magnification of one yellowish feature found at the interface (crystal No. 1); sample No. 2: seed, interface, and new-grown crystal; no yellowish features visible at the interface.
Figure 7. Cross-section, the (10-10) plane, of two examined crystals at UV illumination: crystal No. 1; wavy interface between seed and new grown crystal; yellow luminescence at the interface is well visible; crystal No. 2; flat interface without yellow luminescence.
Figure 8. (0001) planes of seeds and new-grown crystals after DSE: sample No. 1 and sample No. 2.
(2023)
