Optical and electrical properties of dislocations in plastically deformed GaN

• Published in: Journal of crystal growth Vol. 403; pp. 72 - 76
• Main Authors: Yonenaga, I., Ohno, Y., Yao, T., Edagawa, K.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01-10-2014; Elsevier
• Subjects: A1. Defects; A1. Line defects; A1. Optical absorption; A2. Hydride vapor phase epitaxy; A2. Photoluminescence; B2. Nitrides; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Deformation; Dislocations; Edge dislocations; Electric fields; Electrical properties; Exact sciences and technology; Gallium nitrides; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Optical properties; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Photoluminescence; Physics; Vapor phase epitaxy; growth from vapor phase; A2. Hydride vapor phase epitaxy; A1. Optical absorption; A2. Photoluminescence; A1. Defects; A1. Line defects; B2. Nitrides; Electrical conductivity; High density; Luminescence; Photoluminescence; Radiative recombination; VPE; Hydrides; Plastic deformation; Nitrides; Optical properties; Absorption spectra; Optical absorption; Annealing; Vacancies; Electrical properties; Non radiative recombination; Franz-Keldysh effect; III-V compound; Reviews; Edge dislocations; Electric field effects; III-V semiconductors
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2014.06.021

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) [12¯10]-type edge dislocations on the (101¯0) prismatic plane induced several photoluminescence peaks at around 1.8, 1.9 and 2.4eV, which implies the formation of radiative recombination centers of the dislocations. Simultaneously, near-band-edge (3.48eV) 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 (~5.8e/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.
•Optical and electrical properties of fresh dislocations GaN were reviewed.•Their radiative recombination character and band-structure were derived.•Dislocation charges were estimated in the Franz-Keldysh model.•Dislocation conduction by the Frenkel-Poole mechanism was found.