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Semipolar GaN‐based heterostructures on foreign substrates (Phys. Status Solidi B 1/2016)
Author(s) -
Scholz Ferdinand,
Caliebe Marian,
Gahramanova Gulnaz,
Heinz Dominik,
Klein Martin,
Leute Robert A. R.,
Meisch Tobias,
Wang Junjun,
Hocker Matthias,
Thonke Klaus
Publication year - 2016
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201670501
Subject(s) - light emitting diode , optoelectronics , heterojunction , sapphire , quantum well , wafer , materials science , etching (microfabrication) , epitaxy , diode , metalorganic vapour phase epitaxy , laser , optics , layer (electronics) , engineering physics , nanotechnology , physics
Semipolar GaN heterostructures are promising for future green light emitters, because respective GaInN quantum wells are characterized by a reduced piezo‐electric field as compared to their polar counterparts, which is expected to be advantageous for the radiative recombination probability of the carriers in LEDs and laser diodes. However, such structure, requiring an epitaxial growth direction in other than the conventional polar c‐direction, are typically blamed by huge defect densities, particularly if grown on foreign substrates like sapphire. Several papers in this Special Issue (e.g. Scholz et al., Meisch et al., Leung et al., Hashimoto et al., de Mierry et al.) concentrate on a method where the eventually semipolar growth initially proceeds in c‐direction by etching trenches into the sapphire wafer which have a c‐plane side facet. Hence lower defect densities can be realized. The cover figure shows schematically such structure including an in‐situ deposited SiN nanomask layer for further defect reduction (red) and semipolar quantum wells on top (green). Such semipolar LEDs emit quite intense light (bottom pictures) in the green spectral range. See more details in Scholz et al. (pp. 13–22 ) and Meisch et al. (pp. 164–168 ) in this issue.