Vacancy defect distribution in heteroepitaxial -plane GaN grown by hydride vapor phase epitaxy

Characterization of bulk AlN crystals with positron annihilation spectroscopy

“…Also the theoretical prediction about the formation energy of the isolated Ga vacancy was confirmed in those experiments. Studying the differences in Ga vacancy distributions in GaN grown in the Ga-and N-polar directions as well as in nonpolar directions, both in homo-and hetero-epitaxial HVPE samples, has given further information on the formation of the V Ga -O N pairs [12,15,27,28]. Our results demonstrate that Ga vacancies are created thermally as isolated at the high growth temperatures in both HVPE and HNP GaN, but their ability to form V Ga -O N complexes determines the fraction of vacancy defects surviving the cooling down.…”

Defect distribution in a-plane GaN on Al2O3

“…͑i͒ In c-plane material intentionally doped with O to similar concentrations, the Ga vacancy concentration in MOCVD GaN is indeed at least one order of magnitude higher than in HVPE GaN. 15,16 However, the differences in the incorporation of unintentional O from the growth environment are much less evident. This on the other hand can be explained by high density of dislocations whose presence dominates the O incorporation as the O concentration has been shown to be clearly lower in dislocation-free homoepitaxial HVPE GaN.…”

Identification of the Nitrogen Split Interstitial(N−N)Nin GaN

“…Its high cohesive energy imposes particular growth conditions, and as-grown epitaxial film or bulk samples contain a high number of point and extended defects, which influence their electronic and optical properties [1][2][3]. Contrary to the case of GaAs where most of the native intrinsic defects have been identified and characterized in detail [4], this is not the case for GaN.…”