Characterization of dislocations induced by Vickers indentation in GaN for explaining size ratios of dislocation patterns

Characteristics of dislocations induced by Vickers indentation in hydride vapor phase epitaxy GaN were investigated. Dislocations in a rosette pattern have a \(\left\langle {11\overline{2}3} \right\rangle /\left\{ {1\overline{1}00} \right\}\) $〈11\overline{2}3〉/\left\{1\overline{1}00\right\}$ slip system and are mobile under both electron beam and multiphoton excitation. They act as nonradiative recombination sites in the range of 370–560 nm. Dislocations in a flower pattern have a \(\left\langle {11\overline{2}0} \right\rangle /\left\{ {0001} \right\}\) $〈11\overline{2}0〉/\left\{0001\right\}$ slip system and are immobile under excitation. The straight part and loop part of dislocations in a flower pattern are radiative at 440 nm and nonradiative in the range of 370–560 nm, respectively. Dislocations in a triangular area are radiative at 386 nm. The origin of the light emitting property of the straight part in a flower pattern is discussed as the transition between partial dislocations dissociated from an a-type dislocation on (0001). Recalculated dislocation pattern size ratios are well matched with experimentally estimated ones by replacing the dislocation type in a rosette pattern described in the earlier literatures (a-type) with estimated dislocation types in this paper (c + a-type).