Optical properties of fresh dislocations, (a/3)[11•0]-type edge dislocations on the (1¯1•0) prismatic plane, introduced into GaN by plastic deformation at elevated temperatures were investigated by photoluminescence and optical absorption measurements. Plastic deformation acted as an effective passivation, leading to remarkable reduction of near-band-edge photoluminescence intensity centered at 3.48eV and noticeable red-shift of the optical absorption edge. In a model of the Franz–Keldysh effect, the induced edge dislocations posses non-radiative trap sites around 3e/c along their core, resulting in the reduction of free-carrier concentration. Also, the induced dislocations gave rise to some luminescence peaks in the energy range of 1.7 to 2.4eV, differing from the yellow luminescence, which implied the formation of radiative recombination centers by the dislocations.

Optical Properties of Fresh Dislocations in GaN. I.Yonenaga, Y.Ohno, T.Taishi, Y.Tokumoto, H.Makino, T.Yao, Y.Kamimura, K.Edagawa: Journal of Crystal Growth, 2011, 318[1], 415-7