TY - JOUR
T1 - Optical and electrical properties of dislocations in plastically deformed GaN
AU - Yonenaga, I.
AU - Ohno, Y.
AU - Yao, T.
AU - Edagawa, K.
N1 - Funding Information:
We thank Dr. K. Motoki of Sumitomo Electric Industries Ltd. for supplying the GaN bulk crystals and Prof. H. Makino of Kochi University of Technology and Dr. Y. Kamimura of The University of Tokyo for their assistances in conducting the present research. IY thank Prof. A. Uedono for his performance in positron annihilation studies. This work was financially supported in part by a Grant-in-Aid for Scientific Research on Priority Area (No. 21016002 ) and a Grant-in-Aid for Scientific Research (A) (No. 24246103 ) from the Ministry of Education, Science, Sports and Culture, and Technology (MEXT) of Japan.
Publisher Copyright:
© 2014 Elsevier B.V. All rights reserved.
PY - 2014/10/1
Y1 - 2014/10/1
N2 - Optical and electrical properties of fresh dislocations in GaN bulk crystals deformed plastically at elevated temperatures were reviewed. A dislocation band model was proposed. The fresh dislocations of (a/3) [1210]-type edge dislocations on the (1010) prismatic plane induced several photoluminescence peaks at around 1.8, 1.9 and 2.4 eV, which implies the formation of radiative recombination centers of the dislocations. Simultaneously, near-band-edge (3.48 eV) photoluminescence intensity decreased remarkably for a high-density of non-radiative recombination centers originating in deformation-induced abundant Ga-vacancy related clusters. The intensity variation of yellow luminescence with plastic deformation and subsequent annealing did not relate to the native property of dislocations. Variation of optical absorption dependent on the strain in plastically deformed GaN was understood in a model of the Franz-Keldysh effect by the electric fields associated with charged dislocations (∼5.8 e/nm). Scanning spreading resistance microscopic images showed many spots with high conductivity around the induced dislocations, showing electrical conduction along dislocations according to the Frenkel-Poole mechanism.
AB - Optical and electrical properties of fresh dislocations in GaN bulk crystals deformed plastically at elevated temperatures were reviewed. A dislocation band model was proposed. The fresh dislocations of (a/3) [1210]-type edge dislocations on the (1010) prismatic plane induced several photoluminescence peaks at around 1.8, 1.9 and 2.4 eV, which implies the formation of radiative recombination centers of the dislocations. Simultaneously, near-band-edge (3.48 eV) photoluminescence intensity decreased remarkably for a high-density of non-radiative recombination centers originating in deformation-induced abundant Ga-vacancy related clusters. The intensity variation of yellow luminescence with plastic deformation and subsequent annealing did not relate to the native property of dislocations. Variation of optical absorption dependent on the strain in plastically deformed GaN was understood in a model of the Franz-Keldysh effect by the electric fields associated with charged dislocations (∼5.8 e/nm). Scanning spreading resistance microscopic images showed many spots with high conductivity around the induced dislocations, showing electrical conduction along dislocations according to the Frenkel-Poole mechanism.
KW - A1. Defects
KW - A1. Line defects
KW - A1. Optical absorption
KW - A2. Hydride vapor phase epitaxy
KW - A2. Photoluminescence
KW - B2. Nitrides
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U2 - 10.1016/j.jcrysgro.2014.06.021
DO - 10.1016/j.jcrysgro.2014.06.021
M3 - Article
AN - SCOPUS:84910040993
VL - 403
SP - 72
EP - 76
JO - Journal of Crystal Growth
JF - Journal of Crystal Growth
SN - 0022-0248
ER -