Recombination-related properties of a-screw dislocations in GaN: A combined CL, EBIC, TEM study
- V.A. Fok Institute of Physics, St. Petersburg State University (Russian Federation)
- IV. Physikalisches Institut Georg-August Universität Göttingen (Germany)
Cathodoluminescence (CL), electron beam current (EBIC) and transmission electron microscopy (TEM) techniques have been applied to investigate recombination properties and structure of freshly introduced dislocations in low-ohmic GaN crystals. It was confirmed that the only a-screw dislocations exhibited an intense characteristic dislocation-related luminescence (DRL) which persisted up to room temperature and was red-shifted by about 0.3 eV with respect to the band gap energy not only in HVPE but also in MOCVD grown samples. EBIC contrast of the dislocations was found to be temperature independent indicating that the dislocation-related recombination level is situated below 200 meV with respect of conduction band minimum. With the increasing of the magnification of the dislocation TEM cross-sectional images they were found to disappear, probably, due to the recombination enhanced dislocation glide (REDG) under electron beam exposure which was immediately observed in CL investigations on a large scale. The stacking fault ribbon in the core of dissociated a-screw dislocation which form a quantum well for electrons was proposed to play an important role both in DRL spectrum formation and in REDG.
- OSTI ID:
- 22609118
- Journal Information:
- AIP Conference Proceedings, Vol. 1748, Issue 1; Conference: STRANN 2016: 5. international conference on state-of-the-art trends of scientific research of artificial and natural nanoobjects, St. Petersburg (Russian Federation), 26-29 Apr 2016; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BEAM CURRENTS
CATHODOLUMINESCENCE
CHEMICAL VAPOR DEPOSITION
CRYSTALS
ELECTRON BEAMS
GALLIUM NITRIDES
QUANTUM WELLS
RECOMBINATION
RED SHIFT
SCANNING ELECTRON MICROSCOPY
SCREW DISLOCATIONS
SPECTRA
STACKING FAULTS
TEMPERATURE RANGE 0273-0400 K
TRANSMISSION
TRANSMISSION ELECTRON MICROSCOPY